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Array ( [0] => {{Short description|Family of birds}} [1] => {{Other uses}} [2] => {{good article}} [3] => {{Use dmy dates|date=March 2023}} [4] => {{Automatic taxobox [5] => |fossil_range = [[Rupelian]] {{Fossilrange|30|0}} [6] => |image = Trinidad and Tobago hummingbirds composite.jpg [7] => |image_caption = Four hummingbirds
from [[Trinidad and Tobago]] [8] => |taxon = Trochilidae [9] => |authority = [[Nicholas Aylward Vigors|Vigors]], 1825 [10] => |subdivision_ranks = [[Subfamilies]] [11] => |subdivision = {{collapsible list |title = Subfamiles:|bullets = yes|†''[[Eurotrochilus]]''|[[Florisuginae]]|[[Hermit (hummingbird)|Phaethornithinae]]|[[Polytminae]]|[[Lesbiinae]]|[[Patagoninae]]|[[Trochilinae]]|(For an alphabetic species list, see [[List of hummingbird species]])}} [12] => |type_genus = ''[[Trochilus]]'' [13] => |type_genus_authority = [[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]] [14] => }} [15] => '''Hummingbirds''' are [[bird]]s native to the [[Americas]] and comprise the [[Family (biology)|biological family]] '''Trochilidae'''. With approximately 366 species and 113 [[genus|genera]],{{Cite web|last1=Gill |first1=F. |last2=Donsker |first2=D. |last3=Rasmussen |first3=P. |date=29 January 2023 |title=IOC World Bird List (v 13.2), International Ornithological Committee |url=https://www.worldbirdnames.org/new/bow/hummingbirds |access-date=5 March 2023 |publisher= [[Birds of the World: Recommended English Names|IOC World Bird List]]}} they occur from [[Alaska]] to [[Tierra del Fuego]], but most species are found in [[Central America|Central]] and [[South America]].{{cite web |first1=Kathryn |last1=Stonich |title=Hummingbirds of the United States: A Photo List of All Species |url=https://abcbirds.org/blog21/types-of-hummingbirds/ |publisher=American Bird Conservancy |access-date=7 March 2023 |date=26 April 2021}} As of 2024, 21 hummingbird species are listed as [[Endangered species|endangered]] or [[critically endangered]], with numerous species declining in population.{{cite web |title=Hummingbird (search) |url=https://www.iucnredlist.org/search?query=hummingbird&searchType=species |publisher=International Union for Conservation of Nature’s Red List of Threatened Species |access-date=13 March 2024 |date=2024}}{{cite journal |last1=English |first1=Simon G. |last2=Bishop |first2=Christine A. |last3=Wilson |first3=Scott |last4=Smith |first4=Adam C. |title=Current contrasting population trends among North American hummingbirds |journal=Scientific Reports |volume=11 |issue=1 |date=2021-09-15 |page=18369 |issn=2045-2322 |doi=10.1038/s41598-021-97889-x |pmid=34526619 |pmc=8443710 |bibcode=2021NatSR..1118369E }} [16] => [17] => Hummingbirds have varied specialized characteristics to enable rapid, maneuverable flight: exceptional [[metabolism|metabolic capacity]], adaptations to high altitude, sensitive visual and communication abilities, and long-distance migration in some species. Among all birds, male hummingbirds have the widest diversity of [[plumage]] color, particularly in blues, greens, and purples.{{cite journal |author1=Venable, G.X. |author2=Gahm, K. |author3=Prum, R.O. |title=Hummingbird plumage color diversity exceeds the known gamut of all other birds |journal=Communications Biology |volume=5 |issue=1 |pages=576 |date=June 2022 |pmid=35739263 |pmc=9226176 |doi=10.1038/s42003-022-03518-2}} Hummingbirds are the smallest mature birds, measuring {{Convert|7.5|–|13|cm|in|0|abbr=on}} in length. The smallest is the {{Convert|5|cm|in|adj=on|abbr=on}} [[bee hummingbird]], which weighs less than {{Convert|2.0|g|oz|2|abbr=on}}, and the largest is the {{Convert|23|cm|in|0|adj=on|abbr=on}} [[giant hummingbird]], weighing {{Convert|18|–|24|g|oz}}. Noted for long [[beak]]s, hummingbirds are specialized for feeding on flower nectar, but all species also consume small insects. [18] => [19] => They are known as hummingbirds because of the humming sound created by their beating [[Bird's wing|wings]], which flap at high frequencies audible to other birds and humans. They hover at rapid wing-flapping rates, which vary from around 12 beats per second in the largest species to 80 per second in small hummingbirds. [20] => [21] => Hummingbirds have the highest [[basal metabolic rate|mass-specific metabolic rate]] of any [[homeothermic]] animal.{{Cite journal |last=Suarez |first=R.K. |year=1992 |title=Hummingbird flight: Sustaining the highest mass-specific metabolic rates among vertebrates |journal=Experientia |volume=48 |issue=6 |pages=565–570 |doi=10.1007/bf01920240 |pmid=1612136 |s2cid=21328995}}{{Cite journal |last=Hargrove |first=J.L. |year=2005 |title=Adipose energy stores, physical work, and the metabolic syndrome: Lessons from hummingbirds |journal=Nutrition Journal |volume=4 |pages=36 |doi=10.1186/1475-2891-4-36 |pmc=1325055 |pmid=16351726 |doi-access=free }} To conserve energy when food is scarce and at night when not foraging, they can enter [[torpor]], a state similar to [[hibernation]], and slow their [[metabolic rate]] to {{frac|1|15}} of its normal rate.{{Cite web |title=Hummingbirds|publisher=Migratory Bird Center, Smithsonian National Zoological Park |url=http://nationalzoo.si.edu/scbi/migratorybirds/webcam/hummingbirds.cfm |url-status=dead |archive-url=https://archive.today/20120716064758/http://nationalzoo.si.edu/scbi/migratorybirds/webcam/hummingbirds.cfm |archive-date=2012-07-16 |access-date=2013-04-01}} While most hummingbirds do not [[bird migration|migrate]], the [[rufous hummingbird]] has one of the longest migrations among birds, traveling twice per year between Alaska and [[Mexico]], a distance of about {{convert|3900|mi}}. [22] => [23] => Hummingbirds split from their [[Sister taxon|sister group]], the [[Swift (bird)|swifts]] and [[treeswift]]s, around 42 million years ago. The oldest known fossil hummingbird is ''[[Eurotrochilus]]'', from the [[Rupelian]] Stage of Early Oligocene Europe. [24] => [25] => ==Description== [26] => [[File:Mellisuga helenae Size Comparison.svg|thumb|Size of ''Mellisuga helenae'' (bee hummingbird) {{ndash}} the world's smallest bird {{ndash}} compared to a human hand]] [27] => [[File:Bee hummingbird (Mellisuga helenae) adult male non-breeding.jpg|thumb|Adult male bee hummingbird, [[Cuba]]]] [28] => [29] => Hummingbirds are the smallest known and smallest living [[origin of birds|avian theropod dinosaurs]].{{cite journal |last1=Brusatte |first1=SL|last2=O'Connor|first2=JK|last3=Jarvis |first3=ED |title=The origin and diversification of birds |journal=Current Biology |volume=25 |issue=19 |pages=R888–98 |date=October 2015 |pmid=26439352 |doi=10.1016/j.cub.2015.08.003 |s2cid=3099017 |doi-access=free |hdl=10161/11144 |hdl-access=free }}{{cite journal | last=Chiappe | first=Luis M. | title=Downsized dinosaurs: The evolutionary transition to modern birds | journal=Evolution: Education and Outreach| volume=2 | issue=2 | date=16 April 2009 | issn=1936-6426 | doi=10.1007/s12052-009-0133-4 | pages=248–256| s2cid=26966516 | doi-access=free }}{{cite web |last1=Hendry|first1=Lisa |title=Are birds the only surviving dinosaurs? |url=https://www.nhm.ac.uk/discover/why-are-birds-the-only-surviving-dinosaurs.html |publisher=The Trustees of The Natural History Museum, London |access-date=14 April 2023 |date=2023}} The [[Iridescence|iridescent]] colors and highly specialized feathers of many species (mainly in males) give some hummingbirds exotic common names, such as sun gem, fairy, woodstar, sapphire or [[sylph]]. [30] => [31] => ===Morphology=== [32] => Across the estimated 366 species, hummingbird weights range from as small as {{convert|2|g}} to as large as {{convert|20|g}}.{{cite web |title=Hummingbird |url=https://www.britannica.com/animal/hummingbird |publisher=Encyclopaedia Britannica |access-date=7 March 2023 |date=2023}}{{cite web |title=What is a hummingbird? |url=https://nationalzoo.si.edu/migratory-birds/hummingbirds |publisher=Smithsonian’s National Zoo and Conservation Biology Institute |access-date=7 March 2023 |date=2023}} They have characteristic long, narrow beaks (bills) which may be straight (of varying lengths) or highly curved. The bee hummingbird {{ndash}} only {{convert|6|cm}} long and weighing about {{convert|2|g|oz}} {{ndash}} is the world's smallest bird and smallest [[warm-blooded]] [[vertebrate]].{{cite web|publisher=Animal Diversity Web|title= ''Mellisuga helenae''|last1= Glick|first1=Adrienne|url= http://animaldiversity.org/accounts/Mellisuga_helenae/|date=2002 |access-date=14 April 2023}} [33] => [34] => Hummingbirds have compact bodies with relatively long, bladelike wings having anatomical structure enabling [[helicopter]]-like flight in any direction, including the ability to hover. Particularly while hovering, the wing beats produce the humming sounds, which function to alert other birds. In some species, the tail feathers produce sounds used by males during courtship flying. Hummingbirds have extremely rapid wing-beats as high as 80 per second, supported by a high metabolic rate dependent on foraging for sugars from flower nectar. [35] => [36] => [[File:Ruby Throated Hummingbird, F, leg, 430 ESt. NW, 8.22.12 2013-04-12-14.49.36 ZS PMax (8644622066).jpg|thumb|Close-up of toe arrangement in a [[ruby-throated hummingbird]] foot, showing three claw-like toes forward and one backward.]] [37] => Hummingbird legs are short with no [[Bird feet and legs#Tibiotarsus|knees]], and have [[Dactyly#Anisodactyly|feet]] with [[Bird feet and legs#Tarsometatarsus|three toes pointing forward and one backward]] {{ndash}} the [[hallux]].{{cite web |first1=Emily |last1=Hannemann |title=Hummingbird feet: Can hummingbirds walk? |url=https://www.birdsandblooms.com/birding/attracting-hummingbirds/hummingbird-feet/ |publisher=Birds&Blooms |access-date=4 April 2023 |date=12 May 2022}}{{cite web |title=Do hummingbirds have feet? |url=https://www.wildbirdscoop.com/do-hummingbirds-have-feet.html |publisher=Wild Bird Scoop |access-date=4 April 2023 |date=2023}} The toes of hummingbirds are formed as [[claw]]s with ridged inner surfaces to aid gripping onto flower stems or petals. Hummingbirds do not walk on the ground or hop like most birds, but rather shuffle laterally and use their feet to grip while perching, [[preening]] feathers, or nest-building (by females), and during fights to grab feathers of opponents. [38] => [39] => Hummingbirds apply their legs as [[piston]]s for generating [[thrust]] upon taking flight, although the shortness of their legs provides about 20% less propulsion than assessed in other birds.{{cite journal |last1=Tobalske|first1=Bret W. |last2=Altshuler|first2=Douglas L.|last3=Powers|first3=Donald R.|title=Take-off mechanics in hummingbirds (Trochilidae) |journal=The Journal of Experimental Biology |volume=207 |issue=Pt 8 |pages=1345–52 |date=March 2004 |pmid=15010485 |doi=10.1242/jeb.00889 |s2cid=12323960 |url=https://journals.biologists.com/jeb/article/207/8/1345/15063/Take-off-mechanics-in-hummingbirds-Trochilidae|doi-access=free }} During flight, hummingbird feet are tucked up under the body, enabling optimal [[aerodynamics]] and maneuverability. [40] => [41] => Of those species that have been measured during flight, the top flight speeds of hummingbirds exceed {{Convert|15|m/s|km/h mph|abbr=on}}. During [[Courtship display|courtship]], some male species dive from {{Convert|30|m|ft|sigfig=1}} of height above a female at speeds around {{Convert|23|m/s|km/h mph|abbr=on}}.{{Cite journal |last1=Clark |first1=C.J. |last2=Dudley |first2=R. |year=2009 |title=Flight costs of long, sexually selected tails in hummingbirds |journal=Proceedings of the Royal Society B: Biological Sciences |volume=276 |issue=1664 |pages=2109–115 |doi=10.1098/rspb.2009.0090 |pmc=2677254 |pmid=19324747}}{{Cite book |title=The Birds of Ecuador, Field Guide |last1=Ridgely |first1=R.S.|last2=Greenfield|first2= P.G.|publisher=Cornell University Press |year=2001 |isbn=978-0-8014-8721-7 |edition=1}} [42] => [43] => The sexes differ in feather coloration, with males having distinct brilliance and ornamentation of head, neck, wing, and breast feathers. The most typical feather ornament in males is the [[gorget (bird)|gorget]] {{ndash}} a bib-like iridescent neck-feather patch that changes brilliance with the viewing angle to attract females and warn male competitors away from territory. [44] => [45] => ===Life cycle=== [46] => [[File:Allens hummingbird on nest (26198483795).jpg|left|thumb|A nesting female Allen's hummingbird]] [47] => [[File:Allen's Hummingbird Nest (8563916462).jpg|thumb|Each approximately the size of a pea, two eggs in the nest of an Allen's hummingbird]] [48] => [49] => Hummingbirds begin mating when they are a year old. Sex occurs over 3–5 seconds when the male [[Bird anatomy#Reproduction|joins its cloaca]] with the female's, passing sperm to fertilize the female's eggs.{{cite web |last1=Mohrman |first1=Eric |title=How do hummingbirds mate? |url=https://sciencing.com/hummingbirds-mate-4566850.html |publisher=Sciencing, Leaf Media Group Ltd. |access-date=17 April 2023 |date=22 November 2019}} [50] => [51] => Hummingbird females build a nest resembling a small cup about {{convert|1.5|in|cm}} in diameter, commonly attached to a tree branch using spider webs, [[lichen]]s, moss, and loose strings of plant fibers (image). Typically, two [[pea]]-shaped white eggs (image) {{ndash}} the smallest of any bird {{ndash}} are incubated over 2–3 weeks in breeding season. Fed by [[Regurgitation (digestion)|regurgitation]] only from the mother, the chicks [[fledge]] about 3 weeks after hatching.{{cite web |title=Hummingbird facts and family introduction |url=https://www.hummingbirdcentral.com/hummingbird-facts.htm |publisher=Hummingbird Central |access-date=4 April 2023 |date=2023}} [52] => [[File:Friday's Hummingbird Nest (8819601954).jpg|thumb|Hummingbird nestlings ready to fledge]] [53] => [54] => The average lifespan of a [[ruby-throated hummingbird]] is estimated to be 3–5 years, with most deaths occurring in yearlings, although one [[Bird ringing|banded]] ruby-throated hummingbird lived for 9 years and 2 months.{{cite web |title=Ruby-throated hummingbird |url=https://www.allaboutbirds.org/guide/Ruby-throated_Hummingbird/ |publisher=All About Birds, Cornell University Laboratory of Ornithology |access-date=23 April 2023 |date=2023}} Bee hummingbirds live 7–10 years. [55] => [56] => ===Population estimates and threatened species=== [57] => Although most hummingbird species live in remote habitats where their population numbers are difficult to assess, population studies in the United States and Canada indicate that the ruby-throated hummingbird numbers are around 34 million, rufous hummingbirds are around 19 million, [[black-chinned hummingbird|black-chinned]], [[Anna's hummingbird|Anna's]], and [[broad-tailed hummingbird]]s are about 8 million each, [[calliope hummingbird|calliopes]] at 4 million, and [[Costa's hummingbird|Costa's]] and [[Allen's hummingbird]]s are around 2 million each. Several species exist only in the thousands or hundreds. [58] => [59] => According to the [[IUCN Red List|International Union for Conservation of Nature Red List of Threatened Species]] in 2024, 8 hummingbird species are classified as [[critically endangered]], 13 are [[Endangered species|endangered]], 13 are [[vulnerable species|vulnerable]], and 20 species are [[Near-threatened species|near-threatened]]. Two species {{ndash}} the [[Brace's emerald]] (''Riccordia bracei'') and Caribbean emerald (''Riccordia elegans'') {{ndash}} have been declared [[extinction|extinct]]. [60] => [[File:Archilochus colubris (Male).jpg|thumb|left|Male ruby-throated hummingbird (''Archilochus colubris'')]] [61] => Of the 15 species of North American hummingbirds that inhabit the United States and Canada, several have changed their range of distribution, while others showed declines in numbers since the 1970s, including in 2023 with dozens of hummingbird species in decline. As of the 21st century, rufous, Costa's, calliope, broad-tailed, and Allen's hummingbirds are in significant decline, some losing as much as 67% of their numbers since 1970 at nearly double the rate of population loss over the previous 50 years.{{cite news |last1=Chillag|first1= Amy |title=These tiny creatures are losing their battle to survive. Here's what we can do to save them |url=https://www.cnn.com/2023/04/21/world/iyw-rufous-hummingbird-tipping-point-extinction-earth-da |access-date=22 April 2023 |work=CNN |date=21 April 2023}} The ruby-throated hummingbird population {{ndash}} the most populous North American hummingbird {{ndash}} decreased by 17% over the early 21st century. Habitat loss, glass collisions, cat predation, [[pesticide]]s, and possibly [[climate change]] affecting food availability, migration signals, and breeding are factors that may contribute to declining hummingbird numbers. By contrast, Anna's hummingbirds had large population growth at an accelerating rate since 2010, and expanded their range northward to reside year-round in cold winter climates. [62] => [63] => === Superficially similar species === [64] => Some species of [[sunbird]]s {{mdash}} an [[Old World]] group restricted in distribution to [[Eurasia]], Africa, and Australia {{mdash}} resemble hummingbirds in appearance and behavior, but are not related to hummingbirds, as their resemblance is due to [[convergent evolution]].{{Cite journal |last1=Prinzinger |first1=R. |last2=Schafer|first2=T.|last3= Schuchmann|first3= K.L. |year=1992 |title=Energy metabolism, respiratory quotient and breathing parameters in two convergent small bird species : the fork-tailed sunbird ''Aethopyga christinae'' (Nectariniidae) and the chilean hummingbird ''Sephanoides sephanoides'' (Trochilidae) |journal=Journal of Thermal Biology |volume=17 |issue=2 |pages=71–79 |doi=10.1016/0306-4565(92)90001-V}} [65] => [66] => The [[Hemaris|hummingbird moth]] has flying and feeding characteristics similar to those of a hummingbird.{{Cite web |first=Beatriz|last=Moisset |date=2022 |title=Hummingbird moth (Hemaris spp.) |url=https://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/hummingbird_moth.shtml |access-date=2 August 2022 |publisher=Forest Service, US Department of Agriculture}} Hummingbirds may be mistaken for [[hummingbird hawk-moth]]s, which are large, flying insects with hovering capabilities, and exist only in Eurasia.{{cite web|last=White|first=Richard |title=Hummingbird hawk moth, hummingbird and sunbird |url=https://besgroup.org/2015/09/19/hummingbird-hawk-moth-hummingbird-and-sunbird/ |publisher=Bird Ecology Study Group |access-date=8 March 2023 |date=19 September 2015}} [67] => [68] => == Range == [69] => {{See also|List of Apodiformes by population}} [70] => Hummingbirds are restricted to the Americas from south central Alaska to [[Tierra del Fuego]], including the Caribbean. The majority of species occur in tropical and subtropical Central and South America, but several species also breed in temperate climates and some [[hillstar]]s occur even in alpine Andean highlands at altitudes up to {{Convert|5200|m|ft|abbr=on}}.{{cite book|isbn=84-87334-25-3 |last1=Fjeldså|first1=J.|first2=I.|last2=Heynen |year=1999|title=Genus Oreotrochilus. In: del Hoyo, J., A. Elliott, & J. Sargatal. eds. (1999). ''[[Handbook of the Birds of the World]].'' Vol. 5. Barn-owls to Hummingbirds. Lynx Edicions, Barcelona|pages=623–624 |publisher=Lynx Edicions }} [71] => [72] => The greatest [[species richness]] is in humid tropical and subtropical forests of the northern Andes and adjacent foothills, but the number of species found in the [[Atlantic Forest]], Central America or southern [[Mexico]] also far exceeds the number found in southern South America, the Caribbean islands, the United States, and Canada. While fewer than 25 different species of hummingbirds have been recorded from the United States and fewer than 10 from Canada and [[Chile]] each,{{cite web |last1=Jaramillo |first1=A. |author2=Barros, R. |title=Species lists of birds for South American countries and territories: Chile. |url=http://www.museum.lsu.edu/~Remsen/SACCListByCountry.xls |year=2010}} [[Colombia]] alone has more than 160{{cite web |last1=Salaman |first1=P. |author2=Donegan, T. |author3=Caro, D. |title=Checklist to the Birds of Colombia 2009. |url=http://www.proaves.org/IMG/pdf/Aves_de_Colombia_2009-2.pdf |website=Conservation Colombiana |year=2009 |volume=8 |publisher=[[Fundación ProAves]] |archive-url=https://web.archive.org/web/20090824105022/http://www.proaves.org/IMG/pdf/Aves_de_Colombia_2009-2.pdf |archive-date=2009-08-24}} and the comparably small [[Ecuador]] has about 130 species.{{cite web |last1=Freile |first1=J. |title=Species lists of birds for South American countries and territories: Ecuador. |url=http://www.museum.lsu.edu/~Remsen/SACCListByCountry.xls |year=2009}} [73] => [74] => == Taxonomy and systematics == [75] => {{Further|List of hummingbird species}} [76] => [77] => The family Trochilidae was introduced in 1825 by Irish zoologist [[Nicholas Aylward Vigors]] with ''[[Trochilus]]'' as the [[type genus]].{{Cite journal |last=Vigors |first=Nicholas Aylward |author-link=Nicholas Aylward Vigors |year=1825 |title=Observations on the natural affinities that connect the orders and families of birds |url=https://www.biodiversitylibrary.org/page/752841 |journal=Transactions of the Linnean Society of London |volume=14 |issue=3 |pages=395–517 [463] |doi=10.1111/j.1095-8339.1823.tb00098.x}}{{Cite book |last=Bock |first=Walter J. |url=http://digitallibrary.amnh.org/handle/2246/830 |title=History and Nomenclature of Avian Family-Group Names |publisher=American Museum of Natural History |year=1994 |series=Bulletin of the American Museum of Natural History |volume=222 |location=New York |pages=143, 264 |hdl=2246/830}} [78] => In traditional [[Taxonomy (biology)|taxonomy]], hummingbirds are placed in the order [[Apodiformes]], which also contains the [[Swift (bird)|swift]]s, but some taxonomists have separated them into their own order, the Trochiliformes.{{cite book |last1=Sibley |first1=Charles Gald |last2=Ahlquist |first2=Jon Edward |year=1990 |title=Phylogeny and classification of birds |publisher=Yale University Press |location=New Haven, Conn.}} Hummingbirds' wing [[bone]]s are hollow and fragile, making [[fossil]]ization difficult and leaving their evolutionary history poorly documented. Though scientists theorize that hummingbirds originated in South America, where species diversity is greatest, possible ancestors of extant hummingbirds may have lived in parts of Europe and what is southern [[Russia]] today.{{Cite journal |last=Mayr |first=Gerald |date=March 2005 |title=Fossil hummingbirds of the Old World |url=http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/hummingbird_biologist.pdf |url-status=dead |journal=Biologist |volume=52 |issue=1 |pages=12–16 |archive-url=https://web.archive.org/web/20110927045239/http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/hummingbird_biologist.pdf |archive-date=2011-09-27 |access-date=2009-12-14}} [79] => [80] => As of 2023, 366 hummingbird species have been identified. They have been traditionally divided into two [[Subfamily|subfamilies]]: the [[hermit (hummingbird)|hermits]] (subfamily Phaethornithinae) and the typical hummingbirds (subfamily [[Trochilinae]], all the others). Molecular phylogenetic studies have shown, though, that the hermits are [[sister taxon|sister]] to the [[topaz (hummingbird)|topazes]], making the former definition of the Trochilinae not [[monophyletic]]. The hummingbirds form nine major [[clade]]s: the topazes and [[jacobin (hummingbird)|jacobins]], the hermits, the [[Anthracothorax|mangoes]], the [[Lophornis|coquettes]], the [[Heliodoxa|brilliants]], the [[giant hummingbird]] (''Patagona gigas''), the [[mountaingem]]s, the [[Mellisuga|bees]], and the [[Chlorostilbon|emeralds]]. The topazes and jacobins combined have the oldest split with the rest of the hummingbirds. The hummingbird family has the third-greatest number of species of any bird family (after the [[tyrant flycatcher]]s and the [[tanager]]s). [81] => [82] => Fossil hummingbirds are known from the [[Pleistocene]] of [[Brazil]] and the [[Bahamas]], but neither has yet been scientifically described, and fossils and subfossils of a few extant species are known. Until recently, older fossils had not been securely identifiable as those of hummingbirds. [83] => [84] => In 2004, [[Gerald Mayr]] identified two 30-million-year-old hummingbird fossils. The fossils of this primitive hummingbird species, named ''[[Eurotrochilus]] inexpectatus'' ("unexpected European hummingbird"), had been sitting in a [[museum]] drawer in [[Stuttgart]]; they had been unearthed in a clay pit at [[Wiesloch]]–Frauenweiler, south of [[Heidelberg]], [[Germany]], and, because hummingbirds were assumed to have never occurred outside the Americas, were not recognized to be hummingbirds until Mayr took a closer look at them.{{Cite journal |last=Mayr |first=Gerald |date=2004 |title=Old World fossil record of modern-type hummingbirds |journal=Science |volume=304 |issue=5672 |pages=861–864 |bibcode=2004Sci...304..861M |doi=10.1126/science.1096856 |pmid=15131303 |s2cid=6845608}} [85] => [86] => Fossils of birds not clearly assignable to either hummingbirds or a related extinct family, the Jungornithidae, have been found at the [[Messel pit]] and in the [[Caucasus]], dating from 35 to 40 million years ago; this indicates that the split between these two lineages indeed occurred around that time. The areas where these early fossils have been found had a climate quite similar to that of the northern Caribbean or southernmost [[China]] during that time. The biggest remaining mystery at present is what happened to hummingbirds in the roughly 25 million years between the primitive ''Eurotrochilus'' and the modern fossils. The astounding morphological [[adaptation]]s, the decrease in size, and the dispersal to the Americas and extinction in Eurasia all occurred during this timespan. [[DNA–DNA hybridization]] results suggest that the main radiation of South American hummingbirds took place at least partly in the [[Miocene]], some 12 to 13 million years ago, during the uplifting of the northern [[Andes]].{{Cite journal |last1=Bleiweiss |first1=Robert |last2=Kirsch |first2=John A. W. |last3=Matheus |first3=Juan Carlos |year=1999 |title=DNA-DNA hybridization evidence for subfamily structure among hummingbirds |url=http://sora.unm.edu/sites/default/files/journals/auk/v111n01/p0008-p0019.pdf |journal=[[Auk (journal)|Auk]] |volume=111 |issue=1 |pages=8–19 |doi=10.2307/4088500|jstor=4088500 }} [87] => [88] => In 2013, a 50-million-year-old bird fossil unearthed in [[Wyoming]] was found to be a predecessor to hummingbirds and swifts before the groups diverged.{{Cite journal |last1=Ksepka |first1=Daniel T. |last2=Clarke |first2=Julia A. |last3=Nesbitt |first3=Sterling J. |last4=Kulp |first4=Felicia B. |last5=Grande |first5=Lance |year=2013 |title=Fossil evidence of wing shape in a stem relative of swifts and hummingbirds (Aves, Pan-Apodiformes) |journal=Proceedings of the Royal Society B |volume=280 |issue=1761 |page=1761 |doi=10.1098/rspb.2013.0580 |pmc=3652446 |pmid=23760643}} [89] => [90] => == Evolution == [91] => Hummingbirds split from other members of Apodiformes, the insectivorous swifts (family Apodidae) and [[treeswift]]s (family Hemiprocnidae), about 42 million years ago, probably in [[Eurasia]]. Despite their current New World distribution, the earliest species of hummingbird occurred in the early [[Oligocene]] ([[Rupelian]] about 34–28 million years ago) of Europe, belonging to the genus ''Eurotrochilus,'' having similar morphology to modern hummingbirds.{{Cite journal |last=Mayr |first=Gerald |date=2007-01-01 |title=New specimens of the early Oligocene Old World hummingbird Eurotrochilus inexpectatus |url=https://doi.org/10.1007/s10336-006-0108-y |journal=Journal of Ornithology |language=en |volume=148 |issue=1 |pages=105–111 |doi=10.1007/s10336-006-0108-y |issn=2193-7206 |s2cid=11821178}}{{Cite journal |last1=Bochenski |first1=Zygmunt |last2=Bochenski |first2=Zbigniew M. |date=2008-04-01 |title=An Old World hummingbird from the Oligocene: a new fossil from Polish Carpathians |url=https://doi.org/10.1007/s10336-007-0261-y |journal=Journal of Ornithology |language=en |volume=149 |issue=2 |pages=211–216 |doi=10.1007/s10336-007-0261-y |issn=2193-7206 |s2cid=22193761}} [92] => [93] => ===Phylogeny=== [94] => A phylogenetic tree unequivocally indicates that modern hummingbirds originated in South America, with the last common ancestor of all living hummingbirds living around 22 million years ago. [95] => [96] => A map of the hummingbird family tree – reconstructed from analysis of 284 [[species]] – shows rapid diversification from 22 million years ago.{{Cite web |date=3 April 2014 |title=Hummingbirds' 22-million-year-old history of remarkable change is far from complete |url=https://www.sciencedaily.com/releases/2014/04/140403132207.htm |access-date=30 September 2014 |website=ScienceDaily}} Hummingbirds fall into nine main clades – the [[Florisuginae|topazes]], [[Phaethornithinae|hermits]], [[Polytminae|mangoes]], [[Heliantheini|brilliants]], [[Lesbiini|coquettes]], the giant hummingbird, [[Lampornithini|mountaingems]], [[Mellisugini|bees]], and [[Trochilini|emeralds]] – defining their relationship to [[nectar]]-bearing [[flowering plant]]s which attract hummingbirds into new geographic areas.{{Cite journal |last1=McGuire |first1=Jimmy A. |last2=Witt |first2=Christopher C. |last3=Remsen |first3=J.V. Jr. |last4=Dudley |first4=R. |last5=Altshuler |first5=Douglas L. |date=2008 |title=A higher-level taxonomy for hummingbirds |journal=Journal of Ornithology |volume=150 |issue=1 |pages=155–165 |doi=10.1007/s10336-008-0330-x |issn=0021-8375 |s2cid=1918245}} [97] => [98] => [[Molecular phylogenetics|Molecular phylogenetic]] studies of the hummingbirds have shown that the family is composed of nine major clades.{{Cite journal |last1=McGuire |first1=J.A. |last2=Witt |first2=C.C. |last3=Altshuler |first3=D.L. |last4=Remsen |first4=J.V. |date=2007 |title=Phylogenetic systematics and biogeography of hummingbirds: Bayesian and maximum likelihood analyses of partitioned data and selection of an appropriate partitioning strategy |journal=Systematic Biology |volume=56 |issue=5 |pages=837–856 |doi=10.1080/10635150701656360 |pmid=17934998 |doi-access=free}}{{Cite journal |last1=McGuire |first1=J. |last2=Witt |first2=C. |last3=Remsen |first3=J.V. |last4=Corl |first4=A. |last5=Rabosky |first5=D. |last6=Altshuler |first6=D. |last7=Dudley |first7=R. |date=2014 |title=Molecular phylogenetics and the diversification of hummingbirds |journal=Current Biology |volume=24 |issue=8 |pages=910–916 |doi=10.1016/j.cub.2014.03.016 |pmid=24704078 |doi-access=free}} When [[Edward C. Dickinson|Edward Dickinson]] and [[James Van Remsen Jr.]] updated the ''[[Howard and Moore Complete Checklist of the Birds of the World]]'' for the 4th edition in 2013, they divided the hummingbirds into six subfamilies.{{Cite book |title=The Howard & Moore Complete Checklist of the Birds of the World |publisher=Aves Press |year=2013 |isbn=978-0-9568611-0-8 |editor-last=Dickinson |editor-first=E.C. |editor-link=Edward C. Dickinson |edition=4th |volume=1: Non-passerines |location=Eastbourne, UK |pages=105–136 |editor-last2=Remsen |editor-first2=J.V. Jr. |editor-link2=James Van Remsen Jr.}} [99] => [100] => Molecular phylogenetic studies determined the relationships between the major groups of hummingbirds. In the [[cladogram]] below, the English names are those introduced in 1997.{{Cite journal |last1=Bleiweiss |first1=R. |last2=Kirsch |first2=J.A. |last3=Matheus |first3=J.C. |date=1997 |title=DNA hybridization evidence for the principal lineages of hummingbirds (Aves:Trochilidae). |journal=Molecular Biology and Evolution |volume=14 |issue=3 |pages=325–343 |doi=10.1093/oxfordjournals.molbev.a025767 |pmid=9066799 |doi-access=free}} The [[scientific names]] are those introduced in 2013.{{Sfn|Dickinson|Remsen|2013|pp=105–136}} [101] => [102] => {{Clade |style=font-size:100%;line-height:100% [103] => |label1='''Trochilidae''' [104] => |1={{Clade [105] => |1={{Clade [106] => |1=[[Florisuginae]] – topazes [107] => |2=[[Phaethornithinae]] – hermits [108] => }} [109] => |2={{Clade [110] => |1=[[Polytminae]] – mangoes [111] => |2={{Clade [112] => |label1=[[Lesbiinae]] [113] => |1={{Clade [114] => |1=[[Heliantheini]] – brilliants [115] => |2=[[Lesbiini]] – coquettes [116] => }} [117] => |2={{Clade [118] => |1=[[Patagoninae]] – giant hummingbird [119] => |label2=[[Trochilinae]] [120] => |2={{Clade [121] => |1={{Clade [122] => |1=[[Lampornithini]] – mountain gems [123] => |2=[[Mellisugini]] – bees [124] => }} [125] => |2=[[Trochilini]] – emeralds [126] => }} [127] => }} [128] => }} [129] => }} [130] => }} [131] => }} [132] => [133] => While all hummingbirds depend on flower nectar to fuel their high metabolisms and hovering flight, coordinated changes in flower and bill shape stimulated the formation of new species of hummingbirds and plants. Due to this exceptional [[evolution]]ary pattern, as many as 140 hummingbird species can coexist in a specific region, such as the Andes [[Mountain range|range]]. [134] => [135] => The hummingbird [[Phylogenetic tree|evolutionary tree]] shows that one key evolutionary factor appears to have been an altered [[taste receptor]] that enabled hummingbirds to seek nectar.{{Cite journal |last1=Baldwin |first1=M.W. |last2=Toda |first2=Y. |last3=Nakagita |first3=T. |last4=O'Connell |first4=M.J. |last5=Klasing |first5=K.C. |last6=Misaka |first6=T. |last7=Edwards |first7=S.V. |last8=Liberles |first8=S. D. |year=2014 |title=Evolution of sweet taste perception in hummingbirds by transformation of the ancestral umami receptor |journal=Science |volume=345 |issue=6199 |pages=929–933 |bibcode=2014Sci...345..929B |doi=10.1126/science.1255097 |pmc=4302410 |pmid=25146290}} [136] => [137] => Upon maturity, males of a particular species, ''Phaethornis longirostris,'' the [[long-billed hermit]], appear to be evolving a [[dagger]]-like weapon on the beak tip as a secondary [[sexual dimorphism|sexual trait]] to defend [[lek mating|mating areas]].{{Cite journal |author1=Rico-Guevara, A. |author2=Araya-Salas, M. |year=2015 |title=Bills as daggers? A test for sexually dimorphic weapons in a lekking hummingbird |journal=Behavioral Ecology |volume=26 |issue=1 |pages=21–29 |doi=10.1093/beheco/aru182|doi-access=free }} [138] => [139] => ===Geographic diversification=== [140] => The Andes Mountains appear to be a particularly rich environment for hummingbird evolution because diversification occurred simultaneously with mountain uplift over the past 10 million years. Hummingbirds remain in dynamic diversification inhabiting ecological regions across South America, North America, and the Caribbean, indicating an enlarging [[evolutionary radiation]]. [141] => [142] => Within the same geographic region, hummingbird clades coevolved with nectar-bearing plant clades, affecting mechanisms of [[pollination]].{{Cite journal |author1=Abrahamczyk, S. |author2=Renner, S.S. |year=2015 |title=The temporal build-up of hummingbird/plant mutualisms in North America and temperate South America |journal=BMC Evolutionary Biology |volume=15 |issue=1 |page=104 |doi=10.1186/s12862-015-0388-z |pmc=4460853 |pmid=26058608 |doi-access=free |bibcode=2015BMCEE..15..104A }}{{Cite journal |author1=Abrahamczyk, S. |author2=Souto-Vilarós, D. |author3=McGuire, J.A. |author4=Renner, S.S. |year=2015 |title=Diversity and clade ages of West Indian hummingbirds and the largest plant clades dependent on them: a 5–9 Myr young mutualistic system |url=https://zenodo.org/record/890511 |journal=Biological Journal of the Linnean Society |volume=114 |issue=4 |pages=848–859 |doi=10.1111/bij.12476}} The same is true for the [[sword-billed hummingbird]] (''Ensifera ensifera''), one of the morphologically most extreme species, and one of its main food plant clades (''Passiflora'' section ''Tacsonia'').{{Cite journal |last1=Abrahamczyk |first1=S. |last2=Souto-Vilaros |first2=D. |last3=Renner |first3=S. S. |year=2014 |title=Escape from extreme specialization: Passionflowers, bats and the sword-billed hummingbird |journal=Proceedings of the Royal Society B: Biological Sciences |volume=281 |issue=1795 |pages=20140888 |doi=10.1098/rspb.2014.0888 |pmc=4213610 |pmid=25274372}} [143] => [144] => === Coevolution with ornithophilous flowers === [145] => [[File:Purple-throated carib hummingbird feeding.jpg|thumb|[[Purple-throated carib]] feeding at a flower]] [146] => [147] => Hummingbirds are specialized [[nectarivore]]s tied to the [[ornithophily|ornithophilous]] flowers upon which they feed.{{Cite journal |last=Stiles |first=Gary |year=1981 |title=Geographical aspects of bird flower coevolution, with particular reference to Central America |url=https://www.biodiversitylibrary.org/pdf2/002816500087380.pdf |journal=Annals of the Missouri Botanical Garden |volume=68 |issue=2 |pages=323–351 |doi=10.2307/2398801 |jstor=2398801 |s2cid=87692272}} This [[coevolution]] implies that morphological traits of hummingbirds, such as bill length, bill curvature, and body mass, are correlated with morphological traits of plants, such as [[petal|corolla]] length, curvature, and volume.{{Cite journal |last1=Maglianesi |first1=M.A. |last2=Blüthgen |first2=N. |last3=Böhning-Gaese |first3=K. |last4=Schleuning |first4=M. |name-list-style=amp |date=2014 |title=Morphological traits determine specialization and resource use in plant–hummingbird networks in the Neotropics |url=https://www.researchgate.net/publication/268518487 |journal=Ecology |volume=95 |issue=12 |pages=3325–334 |doi=10.1890/13-2261.1|bibcode=2014Ecol...95.3325M }} Some species, especially those with unusual bill shapes, such as the sword-billed hummingbird and the [[eutoxeres|sicklebills]], are coevolved with a small number of flower species. Even in the most specialized hummingbird–plant mutualisms, the number of food plant lineages of the individual hummingbird species increases with time.{{Cite journal |last1=Abrahamczyk |first1=Stefan |last2=Poretschkin |first2=Constantin |last3=Renner |first3=Susanne S. |name-list-style=amp |date=2017 |title=Evolutionary flexibility in five hummingbird/plant mutualistic systems: testing temporal and geographic matching |journal=Journal of Biogeography |volume=44 |issue=8 |pages=1847–855 |doi=10.1111/jbi.12962 |bibcode=2017JBiog..44.1847A |s2cid=90399556}} The bee hummingbird (''Mellisuga helenae'') – the world's smallest bird – evolved to [[dwarfism]] likely because it had to compete with long-billed hummingbirds having an advantage for nectar foraging from specialized flowers, consequently leading the bee hummingbird to more successfully compete for flower foraging against insects.{{Cite magazine |last=Simon, Matt |date=10 July 2015 |title=Absurd Creature of the Week: The World's Tiniest Bird Weighs Less Than a Dime |url=https://www.wired.com/2015/07/absurd-creature-of-the-week-bee-hummingbird |magazine=Wired |access-date=8 March 2017}}{{Cite journal|display-authors=3 |last1=Dalsgaard |first1=Bo |last2=Martín González |first2=Ana M. |last3=Olesen |first3=Jens M. |last4=Ollerton |first4=J |last5=Timmermann |first5=A |last6=Andersen |first6=L. H. |last7=Tossas |first7=A. G. |name-list-style=amp |year=2009 |title=Plant-hummingbird interactions in the West Indies: Floral specialisation gradients associated with environment and hummingbird size |journal=Oecologia |volume=159 |issue=4 |pages=757–766 |bibcode=2009Oecol.159..757D |doi=10.1007/s00442-008-1255-z |pmid=19132403 |s2cid=35922888}} [148] => [149] => [[File:Colibri-thalassinus-001-edit.jpg|thumb|[[Lesser violetear]] at a flower]] [150] => [151] => Many plants pollinated by hummingbirds produce flowers in shades of red, orange, and bright pink, although the birds take nectar from flowers of other colors. Hummingbirds can see [[wavelength]]s into the near-[[ultraviolet]], but hummingbird-pollinated flowers do not reflect these wavelengths as many insect-pollinated flowers do. This narrow [[color spectrum]] may render hummingbird-pollinated flowers relatively inconspicuous to most insects, thereby reducing [[nectar robbing]].{{Cite journal |last1=Rodríguez-Gironés |first1=M.A. |last2=Santamaría |first2=L. |name-list-style=amp |year=2004 |title=Why are so many bird flowers red? |journal=PLOS Biology |volume=2 |issue=10 |page=e350 |doi=10.1371/journal.pbio.0020350 |pmc=521733 |pmid=15486585 |doi-access=free }}{{Cite journal |last=Altschuler |first=D. L. |year=2003 |title=Flower color, hummingbird pollination, and habitat irradiance in four Neotropical forests |journal=[[Biotropica]] |volume=35 |issue=3 |pages=344–355 |doi=10.1646/02113 |s2cid=55929111}} Hummingbird-pollinated flowers also produce relatively weak nectar (averaging 25% sugars) containing a high proportion of [[sucrose]], whereas insect-pollinated flowers typically produce more concentrated nectars dominated by [[fructose]] and [[glucose]].{{Cite journal |last1=Nicolson |first1=S.W. |last2=Fleming |first2=P.A. |name-list-style=amp |year=2003 |title=Nectar as food for birds: the physiological consequences of drinking dilute sugar solutions |url=http://researchrepository.murdoch.edu.au/id/eprint/4725 |journal=Plant Systematics and Evolution |volume=238 |issue=1–4 |pages=139–153 |doi=10.1007/s00606-003-0276-7 |bibcode=2003PSyEv.238..139N |s2cid=23401164}} [152] => [153] => Hummingbirds and the plants they visit for nectar have a tight coevolutionary association, generally called a plant–bird [[mutualism (biology)|mutualistic network]].{{Cite journal |last1=Junker |first1=Robert R. |last2=Blüthgen |first2=Nico |last3=Brehm |first3=Tanja |last4=Binkenstein |first4=Julia |last5=Paulus |first5=Justina |last6=Martin Schaefer |first6=H. |last7=Stang |first7=Martina |name-list-style=amp |date=2012-12-13 |title=Specialization on traits as basis for the niche-breadth of flower visitors and as structuring mechanism of ecological networks |journal=Functional Ecology |volume=27 |issue=2 |pages=329–341 |doi=10.1111/1365-2435.12005 |doi-access=free}} These birds show high specialization and modularity, especially in communities with high species richness. These associations are also observed when closely related hummingbirds, such as two species of the same genus, visit distinct sets of flowering species.{{Cite journal |last1=Martín González |first1=Ana M. |last2=Dalsgaard |first2=Bo |display-authors=etal |date=2015-07-30 |title=The macroecology of phylogenetically structured hummingbird-plant networks |journal=Global Ecology and Biogeography |volume=24 |issue=11 |pages=1212–224 |doi=10.1111/geb.12355 |bibcode=2015GloEB..24.1212M |hdl-access=free |hdl=10026.1/3407}} [154] => [155] => ==Sexual dimorphisms== [156] => [157] => {{multiple image [158] => |image1=Violet-tailed Sylph 2 JCB.jpg [159] => |width1=150 [160] => |caption1=Male [161] => |image2=Violet-tailed Sylph (f) JCB.jpg [162] => |width2=90 [163] => |caption2=Female [164] => |footer=Sexual dimorphism in [[violet-tailed sylph]] [165] => }} [166] => [167] => Hummingbirds exhibit sexual size dimorphism according to [[Rensch's rule]], in which males are smaller than females in small-bodied species, and males are larger than females in large-bodied species.{{Cite journal |last1=Lisle |first1=Stephen P. De |last2=Rowe |first2=Locke |date=2013-11-01 |title=Correlated Evolution of Allometry and Sexual Dimorphism across Higher Taxa |journal=The American Naturalist |volume=182 |issue=5 |pages=630–639 |doi=10.1086/673282 |pmid=24107370 |s2cid=25612107}} The extent of this sexual size difference varies among clades of hummingbirds.{{Cite journal |last1=Berns |first1=Chelsea M. |last2=Adams |first2=Dean C. |date=2012-11-11 |title=Becoming Different But Staying Alike: Patterns of Sexual Size and Shape Dimorphism in Bills of Hummingbirds |journal=Evolutionary Biology |volume=40 |issue=2 |pages=246–260 |doi=10.1007/s11692-012-9206-3 |issn=0071-3260 |s2cid=276492}} For example, the Mellisugini clade (bees) exhibits a large size dimorphism, with females being larger than males. Conversely, the Lesbiini clade (coquettes) displays very little size dimorphism; males and females are similar in size. [168] => Sexual dimorphisms in bill size and shape are also present between male and female hummingbirds, where in many clades, females have longer, more curved bills favored for accessing nectar from tall flowers.{{Cite journal |last1=Temeles |first1=Ethan J. |last2=Miller |first2=Jill S. |last3=Rifkin |first3=Joanna L. |date=2010-04-12 |title=Evolution of sexual dimorphism in bill size and shape of hermit hummingbirds (Phaethornithinae): a role for ecological causation |journal=Philosophical Transactions of the Royal Society of London B: Biological Sciences |volume=365 |issue=1543 |pages=1053–063 |doi=10.1098/rstb.2009.0284 |issn=0962-8436 |pmc=2830232 |pmid=20194168}} For males and females of the same size, females tend to have larger bills. [169] => [170] => Sexual size and bill differences likely evolved due to constraints imposed by courtship, because mating displays of male hummingbirds require complex aerial maneuvers. Males tend to be smaller than females, allowing conservation of energy to [[forage]] competitively and participate more frequently in courtship.{{Cite journal |last=Colwell |first=Robert K. |date=2000-11-01 |title=Rensch's Rule Crosses the Line: Convergent Allometry of Sexual Size Dimorphism in Hummingbirds and Flower Mites |journal=The American Naturalist |volume=156 |issue=5 |pages=495–510 |doi=10.1086/303406 |pmid=29587514 |s2cid=4401233}} Thus, [[sexual selection]] favors smaller male hummingbirds. [171] => [172] => Female hummingbirds tend to be larger, requiring more energy, with longer beaks that allow for more effective reach into crevices of tall flowers for nectar. Thus, females are better at foraging, acquiring flower nectar, and supporting the energy demands of their larger body size. [[Directional selection]] thus favors the larger hummingbirds in terms of acquiring food. [173] => [174] => Another evolutionary cause of this sexual bill dimorphism is that the selective forces from competition for nectar between the sexes of each species drives sexual dimorphism. Depending on which sex holds territory in the species, the other sex having a longer bill and being able to feed on a wide variety of flowers is advantageous, decreasing [[intraspecific competition]]. For example, in species of hummingbirds where males have longer bills, males do not hold a specific territory and have a lek mating system. In species where males have shorter bills than females, males defend their resources, so females benefit from a longer bill to feed from a broader range of flowers. [175] => [176] => ===Feather colors=== [177] => [[File:AnnasHummingbirdPaloAltoNorvig.jpg|upright|thumb|Male Anna's hummingbird showing iridescent crown and gorget feathers]] [178] => [179] => The hummingbird plumage coloration [[gamut]], particularly for blue, green, and purple colors in the gorget and crown of males, occupies 34% of the total color space for bird feathers. White (unpigmented) feathers have the lowest incidence in the hummingbird color gamut. Hummingbird plumage color diversity evolved from sexual and social selection on plumage coloration, which correlates with the rate of hummingbird species development over millions of years. Bright plumage colors in males are part of aggressive [[competition (biology)|competition]] for flower resources and mating. The bright colors result from [[pigment]]ation in the feathers and from [[Prism (optics)|prismal]] cells within the top layers of feathers of the head, gorget, breast, back and wings.{{Cite book |last=Williamson S |url=https://books.google.com/books?id=XtZ1xotyal8C&q=Iridescent+colors+hummingbird+feathers.&pg=PA28 |title=A Field Guide to Hummingbirds of North America. Section: Plumage and Molt |publisher=Houghton Mifflin Harcourt |year=2001 |isbn=978-0-618-02496-4 |pages=13–18}} When [[sunlight]] hits these cells, it is split into wavelengths that reflect to the observer in varying degrees of intensity, with the feather structure acting as a [[diffraction grating]]. Iridescent hummingbird colors result from a combination of refraction and pigmentation, since the diffraction structures themselves are made of [[melanin]], a pigment,{{Cite web |date=2015 |title=Hummingbird characteristics |url=http://www.learner.org/jnorth/search/HummerNotes1.html |url-status=dead |archive-url=https://web.archive.org/web/20161111085045/http://learner.org/jnorth/search/HummerNotes1.html |archive-date=2016-11-11 |access-date=2010-08-30 |website=learner.org |publisher=Annenberg Learner, The Annenberg Foundation}} and may also be colored by [[carotenoid]] pigmentation and more subdued black, brown or gray colors dependent on melanin. [180] => [181] => By merely shifting position, feather regions of a muted-looking bird can instantly become fiery red or vivid green. In courtship displays for one example, males of the colorful Anna's hummingbird orient their bodies and feathers toward the sun to enhance the display value of iridescent plumage toward a female of interest.{{Cite journal |last=Hamilton|first= W.J. |year=1965 |title=Sun-oriented display of the Anna's hummingbird |url=https://sora.unm.edu/sites/default/files/journals/wilson/v077n01/p0038-p0044.pdf |journal=The Wilson Bulletin |volume=77 |issue=1}} [182] => [183] => One study of Anna's hummingbirds found that dietary [[protein]] was an influential factor in feather color, as birds receiving more protein grew significantly more colorful [[crown (anatomy)|crown]] feathers than those fed a low-protein diet.{{Cite journal |author1=Meadows, M.G. |author2=Roudybush, T.E. |author3=McGraw, K.J. |year=2012 |title=Dietary protein level affects iridescent coloration in Anna's hummingbirds, ''Calypte anna'' |journal=Journal of Experimental Biology |volume=215 |issue=16 |pages=2742–750 |doi=10.1242/jeb.069351 |pmc=3404802 |pmid=22837446}} Additionally, birds on a high-protein diet grew yellower (higher [[hue]]) green tail feathers than birds on a low-protein diet. [184] => [185] => == Specialized characteristics and metabolism == [186] => [187] => ===Humming=== [188] => [[File:Calliope hum(a)oga.ogg|thumb|A calliope hummingbird hovering near a [[Bird feeder#Hummingbird feeders|feeder]], creating the "humming" sound from its rapid wingbeats, while [[Bird vocalization|chirping by vocalization]]]] [189] => [190] => Hummingbirds are named for the prominent humming sound their wingbeats make while flying and hovering to feed or interact with other hummingbirds.{{Cite journal|last1=Hightower |first1=Ben J. |last2=Wijnings |first2=Patrick W.A. |last3=Scholte |first3=Rick |last4=Ingersoll |first4=Rivers |last5=Chin |first5=Diana D. |last6=Nguyen |first6=Jade |last7=Shorr |first7=Daniel |last8=Lentink |first8=David |display-authors=3 |date=2021-03-16 |title=How oscillating aerodynamic forces explain the timbre of the hummingbird's hum and other animals in flapping flight |journal=eLife |volume=10 |page=e63107 |doi=10.7554/elife.63107 |issn=2050-084X |pmc=8055270 |pmid=33724182 |doi-access=free }} Humming serves communication purposes by alerting other birds of the arrival of a fellow forager or potential mate. The humming sound derives from [[aerodynamic force]]s generated by the downstrokes and upstrokes of the rapid wingbeats, causing [[Harmonic oscillator|oscillations and harmonics]] that evoke an acoustic quality likened to that of a [[musical instrument]].{{Cite web |last=Eindhoven University of Technology |date=16 March 2021 |title=New measurement technique unravels what gives hummingbird wings their characteristic sound |url=https://phys.org/news/2021-03-technique-unravels-hummingbird-wings-characteristic.html |access-date=13 May 2021 |publisher=Phys.org}} The humming sound of hummingbirds is unique among flying animals, compared to the whine of [[mosquito]]es, buzz of [[bee]]s, and "whoosh" of larger birds. [191] => [192] => The wingbeats causing the hum of hummingbirds during hovering are achieved by [[elastic recoil]] of wing strokes produced by the main flight muscles: the [[pectoralis major]] (the main downstroke muscle) and [[supracoracoideus]] (the main upstroke muscle).{{Cite journal |last1=Ingersoll |first1=Rivers |last2=Lentink |first2=David |date=2018-10-15 |title=How the hummingbird wingbeat is tuned for efficient hovering |url=https://journals.biologists.com/jeb/article/221/20/jeb178228/19706/How-the-hummingbird-wingbeat-is-tuned-for |journal=Journal of Experimental Biology |volume=221 |issue=20 |doi=10.1242/jeb.178228 |issn=1477-9145 |pmid=30323114 |doi-access=free}} [193] => [194] => === Vision === [195] => [[File:Rufous Hummingbird, male 01.jpg|thumb|left|Male rufous hummingbird (''Selasphorus rufus'') displaying a proportionally large eye in relation to its head]] [196] => [197] => Although hummingbird eyes are small in diameter (5–6 mm), they are accommodated in the [[skull]] by reduced skull [[ossification]], and occupy a larger proportion of the skull compared to other birds and animals.{{Cite journal |last1=Ocampo |first1=Diego |last2=Barrantes |first2=Gilbert |last3=Uy |first3=J. Albert C. |date=2018-09-27 |title=Morphological adaptations for relatively larger brains in hummingbird skulls |journal=Ecology and Evolution |volume=8 |issue=21 |pages=10482–10488 |doi=10.1002/ece3.4513 |issn=2045-7758 |pmc=6238128 |pmid=30464820|bibcode=2018EcoEv...810482O }} [198] => [199] => Further, hummingbird eyes have large [[cornea]]s, which comprise about 50% of the total transverse eye diameter, combined with an extraordinary density of [[retinal ganglion cell]]s responsible for visual processing, containing some 45,000 [[neuron]]s per mm².{{Cite journal |author1=Lisney, T.J. |author2=Wylie, D.R. |author3=Kolominsky, J. |author4=Iwaniuk, A.N. |year=2015 |title=Eye morphology and retinal topography in hummingbirds (''Trochilidae Aves'') |url=https://www.karger.com/Article/FullText/441834 |journal=Brain, Behavior and Evolution |volume=86 |issue=3–4 |pages=176–190 |doi=10.1159/000441834 |pmid=26587582 |doi-access=free}} The enlarged cornea relative to total eye diameter serves to increase the amount of light perception by the eye when the [[pupil]] is dilated maximally, enabling [[nocturnal]] flight. [200] => [201] => During evolution, hummingbirds adapted to the navigational needs of visual processing while in rapid flight or hovering by development of the exceptionally dense array of retinal neurons, allowing for increased [[spatial resolution]] in the [[geometric terms of location|lateral and frontal]] [[visual field]]s. [[Morphology (biology)|Morphological]] studies of the hummingbird brain showed that neuronal [[hypertrophy]] {{Ndash}} relatively the largest in any bird {{Ndash}} exists in a region called the ''[[pretectal area|pretectal]] nucleus lentiformis [[Midbrain|mesencephali]]'' (called the ''nucleus of the [[optic tract]]'' in mammals) responsible for refining dynamic visual processing while hovering and during rapid flight.{{Cite journal |author1=Iwaniuk, A.N. |author2=Wylie, D.R. |year=2007 |title=Neural specialization for hovering in hummingbirds: hypertrophy of the pretectal nucleus Lentiformis mesencephali |url=http://www.psych.ualberta.ca/~dwylie/Iwaniuk%20and%20Wylie%20JCN%202007.pdf |journal=Journal of Comparative Neurology |volume=500 |issue=2 |pages=211–221 |doi=10.1002/cne.21098 |pmid=17111358 |s2cid=15678218}}{{Cite journal |last1=Gaede |first1=A.H. |last2=Goller |first2=B. |last3=Lam |first3=J.P. |last4=Wylie |first4=D.R. |last5=Altshuler |first5=D.L. |year=2017 |title=Neurons responsive to global visual motion have unique tuning properties in hummingbirds |journal=Current Biology |volume=27 |issue=2 |pages=279–285 |doi=10.1016/j.cub.2016.11.041 |pmid=28065606 |doi-access=free |s2cid=28314419}} [202] => [203] => The enlargement of the brain region responsible for visual processing indicates an enhanced ability for perception and processing of fast-moving visual stimuli encountered during rapid forward flight, insect foraging, competitive interactions, and high-speed courtship.{{Cite web |date=5 January 2017 |title=Hummingbirds see motion in an unexpected way |url=https://www.sciencedaily.com/releases/2017/01/170105123115.htm |access-date=24 April 2017 |website=ScienceDaily}} A study of broad-tailed hummingbirds indicated that hummingbirds have a fourth [[Photoreceptor cell#Difference between rods and cones|color-sensitive visual cone]] (humans have three) that detects [[Ultraviolet|ultraviolet light]] and enables discrimination of [[Color#Spectral colors|non-spectral colors]], possibly having a role in flower identity, courtship displays, territorial defense, and predator evasion.{{Cite journal |author1=Stoddard, M.C. |author2=Eyster, H.N. |author3=Hogan, B.G. |author4=Morris, D.H. |author5=Soucy, E.R. |author6=Inouye, D.W. |date=2020-06-15 |title=Wild hummingbirds discriminate nonspectral colors |journal=Proceedings of the National Academy of Sciences |volume=117 |issue=26 |display-authors=3 |pages=15112–122 |doi=10.1073/pnas.1919377117 |issn=0027-8424 |pmc=7334476 |pmid=32541035 |bibcode=2020PNAS..11715112S |doi-access=free}} The fourth color cone would extend the range of visible colors for hummingbirds to perceive ultraviolet light and color combinations of feathers and gorgets, colorful plants, and other objects in their environment, enabling detection of as many as five non-spectral colors, including purple, ultraviolet-red, ultraviolet-green, ultraviolet-yellow, and ultraviolet-purple. [204] => [205] => Hummingbirds are highly sensitive to stimuli in their visual fields, responding to even minimal motion in any direction by reorienting themselves in midflight.{{Cite journal |author1=Goller, B. |author2=Altshuler, D.L. |year=2014 |title=Hummingbirds control hovering flight by stabilizing visual motion |journal=Proceedings of the National Academy of Sciences |volume=111 |issue=51 |pages=18375–380 |bibcode=2014PNAS..11118375G |doi=10.1073/pnas.1415975111 |pmc=4280641 |pmid=25489117 |doi-access=free}} Their visual sensitivity allows them to precisely hover in place while in complex and dynamic natural environments, functions enabled by the [[lentiform nucleus]] which is tuned to fast-pattern velocities, enabling highly tuned control and collision avoidance during forward flight. [206] => [207] => === Song, vocal learning, and hearing === [208] => [[File:Acoustic-Divergence-with-Gene-Flow-in-a-Lekking-Hummingbird-with-Complex-Songs-pone.0109241.s010.oga|thumb|Complex songs of male [[wedge-tailed sabrewing]] hummingbirds (''Campylopterus curvipennis'') in [[lek mating|mating leks]] of eastern Mexico{{cite journal | last1=González | first1=Clementina | last2=Ornelas | first2=Juan Francisco | title=Acoustic divergence with gene flow in a lekking hummingbird with complex songs | journal=PLOS ONE| volume=9 | issue=10 | date=2014-10-01 | issn=1932-6203 | doi=10.1371/journal.pone.0109241 | page=e109241|pmid=25271429|pmc=4182805 | bibcode=2014PLoSO...9j9241G | doi-access=free }}]] [209] => [210] => Many hummingbird species exhibit a diverse vocal repertoire of chirps, squeaks, whistles and buzzes.{{cite journal |author1=Duque, F.G. |author2=Carruth, L.L. |title=Vocal communication in hummingbirds |journal=Brain, Behavior and Evolution |volume=97 |issue=3–4 |pages=241–252 |date=2022 |pmid=35073546 |doi=10.1159/000522148 |s2cid=246278322 |url=https://www.karger.com/Article/FullText/522148|type=Review|doi-access=free }}{{Cite web |date=2015 |title=Song sounds of various hummingbird species |url=https://www.allaboutbirds.org/guide/browse.aspx?shape=37,11 |access-date=25 June 2016 |website=All About Birds |publisher=The Cornell Lab of Ornithology, Cornell University, Ithaca, New York}} Vocalizations vary in complexity and spectral content during social interactions, foraging, territorial defense, courtship, and mother-nestling communication. Territorial vocal signals may be produced in rapid succession to discourage aggressive encounters, with the chirping rate and loudness increasing when intruders persist. During the breeding season, male and female hummingbirds vocalize as part of courtship. [211] => [212] => Hummingbirds exhibit vocal production learning to enable song variation {{ndash}} "dialects" that exist across the same species. For example, the blue-throated hummingbird's song differs from typical oscine songs in its wide frequency range, extending from 1.8 kHz to about 30 kHz.{{Cite journal |last1=Pytte |first1=C.L. |last2=Ficken |first2=M.S. |last3=Moiseff |first3=A. |year=2004 |title=Ultrasonic singing by the blue-throated hummingbird: A comparison between production and perception |url=https://www.researchgate.net/publication/8542654 |journal=Journal of Comparative Physiology A |volume=190 |issue=8 |pages=665–673 |doi=10.1007/s00359-004-0525-4 |pmid=15164219 |s2cid=7231117}} It also produces [[ultrasound|ultrasonic]] vocalizations which do not function in communication. As blue-throated hummingbirds often alternate singing with catching small flying insects, it is possible the ultrasonic clicks produced during singing disrupt insect flight patterns, making insects more vulnerable to predation. Anna's, Costa's, long-billed hermits, and Andean hummingbirds have song dialects that vary across habitat locations and phylogenetic clades.{{cite journal |author1=Duque, F.G. |author2=Rodríguez-Saltos, C.A. |author3=Wilczynsk, W. |title=High-frequency vocalizations in Andean hummingbirds |journal=Current Biology |volume=28 |issue=17 |pages=R927–R928 |date=September 2018 |pmid=30205060 |doi=10.1016/j.cub.2018.07.058 |s2cid=52188456 |doi-access=free }} [213] => [[File:Calypte anna - Anna's Hummingbird XC109651.mp3|thumb|Song of male Anna's hummingbird (''Calypte anna'')]] [214] => [215] => The avian vocal organ, the [[Syrinx (bird anatomy)|syrinx]], plays an important role in understanding hummingbird song production.{{Cite journal |last1=Monte |first1=Amanda |last2=Cerwenka |first2=Alexander F. |last3=Ruthensteiner |first3=Bernhard |last4=Gahr |first4=Manfred |last5=Düring |first5=Daniel N. |date=2020-07-06 |title=The hummingbird syrinx morphome: a detailed three-dimensional description of the black jacobin's vocal organ |journal=BMC Zoology |volume=5 |issue=1 |pages=7 |doi=10.1186/s40850-020-00057-3 |issn=2056-3132 |doi-access=free |s2cid=220509046|hdl=20.500.11850/429165 |hdl-access=free }} What makes the hummingbird's syrinx different from that of other birds in the Apodiformes order is the presence of internal muscle structure, accessory cartilages, and a large [[Eardrum|tympanum]] that serves as an attachment point for external muscles, all of which are adaptations thought to be responsible for the hummingbird's increased ability in pitch control and large frequency range.{{Cite journal |last1=Riede |first1=Tobias |last2=Olson |first2=Christopher R. |date=2020-02-06 |title=The vocal organ of hummingbirds shows convergence with songbirds |journal=Scientific Reports |language=en |volume=10 |issue=1 |pages=2007 |bibcode=2020NatSR..10.2007R |doi=10.1038/s41598-020-58843-5 |issn=2045-2322 |pmc=7005288 |pmid=32029812}} [216] => [217] => Hummingbird songs originate from at least seven specialized [[nucleus (neuroanatomy)|nuclei]] in the [[forebrain]].{{Cite journal |last1=Jarvis |first1=Erich D. |last2=Ribeiro |first2=Sidarta |last3=da Silva |first3=Maria Luisa |last4=Ventura |first4=Dora |last5=Vielliard |first5=Jacques |last6=Mello |first6=Claudio V. |year=2000 |title=Behaviourally driven gene expression reveals song nuclei in hummingbird brain |journal=Nature |volume=406 |issue=6796 |pages=628–632 |bibcode=2000Natur.406..628J |doi=10.1038/35020570 |pmc=2531203 |pmid=10949303}}{{Cite journal |last=Gahr M. |year=2000 |title=Neural song control system of hummingbirds: comparison to swifts, vocal learning (Songbirds) and nonlearning (Suboscines) passerines, and vocal learning (Budgerigars) and nonlearning (Dove, owl, gull, quail, chicken) nonpasserines |journal=J Comp Neurol |volume=486 |issue=2 |pages=182–196 |doi=10.1002/1096-9861(20001016)426:2<182::AID-CNE2>3.0.CO;2-M |pmid=10982462 |s2cid=10763166}} A [[genetic expression]] study showed that these nuclei enable [[vocal learning]] (ability to acquire vocalizations through imitation), a rare trait known to occur in only two other groups of birds ([[parrot]]s and [[songbird]]s) and a few groups of mammals (including humans, [[cetacea|whales and dolphins]], and [[bat]]s). Within the past 66 million years, only hummingbirds, parrots, and songbirds out of 23 bird [[order (biology)|orders]] may have independently evolved seven similar forebrain structures for singing and vocal learning, indicating that evolution of these structures is under strong [[epigenetics|epigenetic]] constraints possibly derived from a common ancestor.{{Cite journal |last1=Renne |first1=Paul R. |last2=Deino |first2=Alan L. |last3=Hilgen |first3=Frederik J. |last4=Kuiper |first4=Klaudia F. |last5=Mark |first5=Darren F. |last6=Mitchell |first6=William S. |last7=Morgan |first7=Leah E. |last8=Mundil |first8=Roland |last9=Smit |first9=Jan |display-authors=3 |date=7 February 2013 |title=Time Scales of Critical Events Around the Cretaceous-Paleogene Boundary |url=http://www.cugb.edu.cn/uploadCms/file/20600/20131028144132060.pdf |url-status=dead |journal=Science |volume=339 |issue=6120 |pages=684–687 |bibcode=2013Sci...339..684R |doi=10.1126/science.1230492 |pmid=23393261 |archive-url=https://web.archive.org/web/20170207164818/http://www.cugb.edu.cn/uploadCms/file/20600/20131028144132060.pdf |archive-date=7 February 2017 |access-date=1 April 2018 |s2cid=6112274}} [218] => [219] => Generally, birds have been assessed to vocalize and hear in the range of 2–5 kHz, with hearing sensitivity falling with higher frequencies. In the [[Ecuadorian hillstar]] (''Oreotrochilus chimborazo''), vocalizations were recorded in the wild to be at a frequency above 10 kHz, well outside of the known hearing ability of most birds. Song system nuclei in the hummingbird brain are similar to those songbird brains, but the hummingbird brain has specialized regions involved for song processing. [220] => [221] => === Metabolism === [222] => [223] => Hummingbirds have the highest metabolism of all vertebrate animals – a necessity to support the rapid beating of their wings during hovering and fast forward flight.{{Cite journal |last1=Altshuler |first1=D.L. |last2=Dudley |first2=R. |year=2002 |title=The ecological and evolutionary interface of hummingbird flight physiology |journal=The Journal of Experimental Biology |volume=205 |issue=Pt 16 |pages=2325–336 |doi=10.1242/jeb.205.16.2325 |pmid=12124359|url=https://journals.biologists.com/jeb/article/205/16/2325/9117/The-ecological-and-evolutionary-interface-of}} During flight and hovering, oxygen consumption per gram of muscle tissue in a hummingbird is about 10 times higher than that measured in elite human athletes. Hummingbirds achieve this extraordinary capacity for oxygen consumption by an exceptional density and proximity of capillaries and [[mitochondrion|mitochondria]] in their flight muscles.{{cite journal |author1=Suarez R.K. |author2=Lighton J.R. |author3=Brown G.S. |author4=Mathieu-Costello O. |title=Mitochondrial respiration in hummingbird flight muscles |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=88 |issue=11 |pages=4870–3 |date=June 1991 |pmid=2052568 |pmc=51768 |doi=10.1073/pnas.88.11.4870|bibcode=1991PNAS...88.4870S |doi-access=free }} [224] => [225] => Hummingbirds are rare among vertebrates in their ability to rapidly make use of ingested sugars to fuel energetically expensive hovering flight, powering up to 100% of their metabolic needs with the sugars they drink.{{Cite journal |last1=Welch |first1=K.C. Jr. |last2=Chen |first2=C.C. |year=2014 |title=Sugar flux through the flight muscles of hovering vertebrate nectarivores: A review |journal=Journal of Comparative Physiology B |volume=184 |issue=8 |pages=945–959 |doi=10.1007/s00360-014-0843-y |pmid=25031038 |s2cid=11109453}} Hummingbird flight muscles have extremely high capacities for [[Redox|oxidizing]] [[carbohydrate]]s and [[fatty acid]]s via [[hexokinase]], [[carnitine palmitoyltransferase]], and [[citrate synthase]] [[enzyme]]s at rates that are the highest known for vertebrate [[skeletal muscle]].{{cite journal | last1=Suarez |first1=R.K. |last2=Lighton |first2=J.R. |last3=Moyes |first3=C.D.|last4=Brown|first4=G.S.|last5=Gass|first5=C.L.|last6=Hochachka |first6=P.W. |display-authors=3 | title = Fuel selection in rufous hummingbirds: ecological implications of metabolic biochemistry | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 87 | issue = 23 | pages = 9207–10 | date = 1 December 1990 | pmid = 2251266 | pmc = 55133 | doi = 10.1073/pnas.87.23.9207|bibcode=1990PNAS...87.9207S |doi-access=free }} To sustain rapid wingbeats during flight and hovering, hummingbirds expend the [[human equivalent]] of 150,000 [[calorie]]s per day,{{cite web |last1=Barlett|first1=Paige |title=Fueling the hummingbird's extreme biology |url=https://www.hopkinsmedicine.org/research/advancements-in-research/fundamentals/in-depth/fueling-the-hummingbirds-extreme-biology |publisher=Johns Hopkins Medicine |access-date=27 March 2023 |date=2018}} an amount estimated to be 10 times the energy consumption by a [[marathon]] runner in competition.{{cite web |last1=Campbell|first1=Don |title=Hummingbird metabolism unique in burning glucose and fructose equally |url=https://utsc.utoronto.ca/news-events/archived/hummingbird-metabolism-unique-burning-glucose-and-fructose-equally |publisher=University of Toronto - Scarborough |access-date=27 March 2023 |date=3 December 2013}} [226] => [227] => Hummingbirds can use newly ingested sugars to fuel hovering flight within 30–45 minutes of consumption.{{Cite journal |last1=Chen|first1=Chris Chin Wah |last2=Welch|first2=Kenneth Collins |year=2014 |title=Hummingbirds can fuel expensive hovering flight completely with either exogenous glucose or fructose |journal=Functional Ecology |volume=28 |issue=3 |pages=589–600 |doi=10.1111/1365-2435.12202 |doi-access=free|bibcode=2014FuEco..28..589C }}{{Cite journal |last1=Welch |first1=K.C. Jr. |last2=Suarez |first2=R.K. |year=2007 |title=Oxidation rate and turnover of ingested sugar in hovering Anna's (''Calypte anna'') and rufous (''Selasphorus rufus'') hummingbirds |journal=Journal of Experimental Biology |volume=210 |issue=Pt 12 |pages=2154–162 |doi=10.1242/jeb.005363 |pmid=17562889 |doi-access=free}} These data suggest that hummingbirds are able to oxidize sugar in flight muscles at rates rapid enough to satisfy their extreme metabolic demands {{ndash}} as indicated by a 2017 review showing that hummingbirds have in their flight muscles a mechanism for "direct oxidation" of sugars into maximal [[Adenosine triphosphate|ATP]] yield to support a high metabolic rate for hovering, foraging at altitude, and migrating.{{Cite journal |last1=Suarez |first1=Raul |last2=Welch |first2=Kenneth |date=12 July 2017 |title=Sugar metabolism in hummingbirds and nectar bats |journal=Nutrients |volume=9 |issue=7 |page=743 |doi=10.3390/nu9070743 |issn=2072-6643 |pmc=5537857 |pmid=28704953 |doi-access=free}} This adaptation occurred through the [[natural selection|evolutionary]] loss of a key [[gene]], [[fructose-bisphosphatase 2]] (''FBP2''), coinciding with the onset of hovering by hummingbirds estimated by fossil evidence to be some 35 million years ago.{{cite web |first=Viviane |last=Callier |title=Evolution Turns These Knobs to Make a Hummingbird Hyperquick and a Cavefish Sluggishly Slow|url=https://www.scientificamerican.com/article/evolution-turns-these-knobs-to-make-a-hummingbird-hyperquick-and-a-cavefish-sluggishly-slow/|publisher=Scientific American |date=24 February 2023 |access-date=27 February 2023}}{{cite journal|display-authors=3 |last1=Osipova |first1=Ekaterina |last2=Barsacchi |first2=Rico |last3=Brown |first3=Tom |last4=Sadanandan |first4=Keren |last5=Gaede |first5=Andrea H. |last6=Monte |first6=Amanda |last7=Jarrells |first7=Julia |last8=Moebius |first8=Claudia |last9=Pippel |first9=Martin |last10=Altshuler |first10=Douglas L. |last11=Winkler |first11=Sylke |last12=Bickle |first12=Marc |last13=Baldwin |first13=Maude W. |last14=Hiller |first14=Michael |title=Loss of a gluconeogenic muscle enzyme contributed to adaptive metabolic traits in hummingbirds |journal=Science|volume=379 |issue=6628 |date=2023-01-13 |issn=0036-8075 |doi=10.1126/science.abn7050 |pages=185–190|pmid=36634192 |bibcode=2023Sci...379..185O |s2cid=255749672 |url=https://www.science.org/doi/10.1126/science.abn7050}} Without ''FBP2'', [[glycolysis]] and mitochondrial respiration in flight muscles are enhanced, enabling hummingbirds to metabolize sugar more efficiently for energy. [228] => [229] => By relying on newly ingested sugars to fuel flight, hummingbirds reserve their limited fat stores to sustain their overnight [[fasting]] during torpor or to power migratory flights. Studies of hummingbird metabolism address how a [[bird migration|migrating]] ruby-throated hummingbird can cross {{Convert|800|km|mi|abbr=on}} of the [[Gulf of Mexico]] on a nonstop flight. This hummingbird, like other long-distance migrating birds, stores fat as a fuel reserve, augmenting its weight by as much as 100%, then enabling metabolic fuel for flying over open water.{{Cite book |last1=Skutch |first1=Alexander F. |url=https://archive.org/details/lifeofhummingbir00skut |title=The Life of the Hummingbird |last2=Singer |first2=Arthur B. |publisher=Crown Publishers |year=1973 |isbn=978-0-517-50572-4 |location=New York |url-access=registration |name-list-style=amp}} The amount of fat (1–2 g) used by a migrating hummingbird to cross the Gulf of Mexico in a single flight is similar to that used by a human climbing about {{convert|50|ft|m}}. [230] => [231] => The [[heart rate]] of hummingbirds can reach as high as 1,260 beats per minute, a rate measured in a [[blue-throated hummingbird]] with a [[respiratory rate|breathing rate]] of 250 breaths per minute at rest.{{Cite journal |last=Lasiewski |first=Robert C. |year=1964 |title=Body temperatures, heart and breathing rate, and evaporative water loss in hummingbirds |journal=Physiological Zoology |volume=37 |issue=2 |pages=212–223 |doi=10.1086/physzool.37.2.30152332 |s2cid=87037075}} [232] => [233] => ===Heat dissipation=== [234] => [235] => The high metabolic rate of hummingbirds – especially during rapid forward flight and hovering – produces increased body heat that requires specialized mechanisms of [[thermoregulation]] for heat dissipation, which becomes an even greater challenge in hot, humid climates.{{Cite journal |last1=Powers |first1=Donald R. |last2=Langland |first2=Kathleen M. |last3=Wethington |first3=Susan M. |last4=Powers |first4=Sean D. |last5=Graham |first5=Catherine H. |last6=Tobalske |first6=Bret W. |year=2017 |title=Hovering in the heat: effects of environmental temperature on heat regulation in foraging hummingbirds |journal=Royal Society Open Science |volume=4 |issue=12 |page=171056 |doi=10.1098/rsos.171056 |issn=2054-5703 |pmc=5750011 |pmid=29308244}} Hummingbirds dissipate heat partially by [[evaporation]] through exhaled air, and from body structures with thin or no feather covering, such as around the eyes, shoulders, under the wings ([[patagium|patagia]]), and feet.{{Cite journal |last1=Evangelista |first1=Dennis |last2=Fernández |first2=María José |last3=Berns |first3=Madalyn S. |last4=Hoover |first4=Aaron |last5=Dudley |first5=Robert |year=2010 |title=Hovering energetics and thermal balance in Anna's hummingbirds (''Calypte anna'') |url=https://www.researchgate.net/publication/42638033 |journal=Physiological and Biochemical Zoology |volume=83 |issue=3 |pages=406–413 |doi=10.1086/651460 |issn=1522-2152 |pmid=20350142 |s2cid=26974159}}{{Cite web |first=Matt|last=Soniak |date=2 February 2016 |title=Infrared video shows how hummingbirds shed heat through their eyes and feet |url=https://www.mentalfloss.com/article/74571/infrared-video-shows-how-hummingbirds-shed-heat-through-their-eyes-and-feet |access-date=14 January 2020 |publisher=Mental Floss}} [236] => [237] => While hovering, hummingbirds do not benefit from the heat loss by [[convection|air convection]] during forward flight, except for air movement generated by their rapid wing-beat, possibly aiding convective heat loss from the extended feet.{{Cite journal |first=Miklos D.F.|last=Udvardy |date=1983 |title=The role of the feet in behavioral thermoregulation of hummingbirds |url=https://sora.unm.edu/sites/default/files/journals/condor/v085n03/p0281-p0285.pdf |journal=Condor |volume=85 |issue=3 |pages=281–285 |doi=10.2307/1367060|jstor=1367060 }} Smaller hummingbird species, such as the calliope, appear to adapt their relatively higher [[surface-to-volume ratio]] to improve convective cooling from air movement by the wings. When air temperatures rise above {{Convert|36|C}}, thermal gradients driving heat passively by convective dissipation from around the eyes, shoulders, and feet are reduced or eliminated, requiring heat dissipation mainly by evaporation and [[exhalation]]. In cold climates, hummingbirds retract their feet into breast feathers to eliminate skin exposure and minimize heat dissipation. [238] => [239] => === Kidney function === [240] => [241] => The dynamic range of metabolic rates in hummingbirds{{Cite journal |last1=Suarez |first1=R.K. |last2=Gass |first2=C.L. |year=2002 |title=Hummingbirds foraging and the relation between bioenergetics and behavior |journal=Comparative Biochemistry and Physiology |series=Part A |volume=133 |issue=2 |pages=335–343 |doi=10.1016/S1095-6433(02)00165-4 |pmid=12208304}} requires a parallel dynamic range in [[kidney]] function.{{Cite journal |last1=Bakken |first1=B.H. |last2=McWhorter |first2=T.J. |last3=Tsahar |first3=E. |last4=Martinez del Rio |first4=C. |year=2004 |title=Hummingbirds arrest their kidneys at night: diel variation in glomerular filtration rate in Selasphorus platycercus |journal=The Journal of Experimental Biology |volume=207 |issue=25 |pages=4383–391 |doi=10.1242/jeb.01238 |pmid=15557024 |doi-access=free|hdl=2440/55466 |hdl-access=free }} During a day of nectar consumption with a corresponding high water intake that may total five times the body weight per day, hummingbird kidneys process water via [[renal function|glomerular filtration rates]] (GFR) in amounts proportional to water consumption, thereby avoiding [[water intoxication|overhydration]].{{Cite journal |last1=Bakken |first1=B.H. |last2=Sabat |first2=P. |year=2006 |title=Gastrointestinal and renal responses to water intake in the green-backed firecrown (Sephanoides sephanoides), a South American hummingbird |journal=AJP: Regulatory, Integrative and Comparative Physiology |volume=291 |issue=3 |pages=R830–836 |doi=10.1152/ajpregu.00137.2006 |pmid=16614056 |hdl-access=free |s2cid=2391784 |hdl=10533/177203}} During brief periods of water deprivation, however, such as in nighttime torpor, GFR drops to zero, preserving body water. [242] => [243] => Hummingbird kidneys also have a unique ability to control the levels of [[electrolyte]]s after consuming nectars with high amounts of [[sodium]] and [[chloride]] or none, indicating that kidney and glomerular structures must be highly specialized for variations in nectar [[Mineral (nutrient)|mineral]] quality.{{Cite journal |last1=Lotz |first1=Chris N. |last2=Martínez Del Rio |first2=Carlos |year=2004 |title=The ability of rufous hummingbirds ''Selasphorus rufus'' to dilute and concentrate urine |journal=Journal of Avian Biology |volume=35 |pages=54–62 |doi=10.1111/j.0908-8857.2004.03083.x}} Morphological studies on Anna's hummingbird kidneys showed adaptations of high [[capillary]] density in close proximity to [[nephron]]s, allowing for precise regulation of water and electrolytes.{{Cite journal |author1=Beuchat, C.A. |author2=Preest, M.R. |author3=Braun, E.J. |year=1999 |title=Glomerular and medullary architecture in the kidney of Anna's Hummingbird |journal=Journal of Morphology |volume=240 |issue=2 |pages=95–100 |doi=10.1002/(sici)1097-4687(199905)240:2<95::aid-jmor1>3.0.co;2-u |pmid=29847878 |s2cid=44156688}} [244] => [245] => ===Hemoglobin adaptation to altitude=== [246] => [247] => Dozens of hummingbird species live year-round in tropical mountain habitats at high altitudes, such as in the Andes over ranges of {{Convert|1500|m|ft}} to {{Convert|5200|m|ft}} where the [[Blood gas tension|partial pressure of oxygen]] in the air is reduced, a condition of [[hypoxia (medical)|hypoxic challenge]] for the high metabolic demands of hummingbirds.{{Cite journal |last1=Projecto-Garcia |first1=Joana |last2=Natarajan |first2=Chandrasekhar |last3=Moriyama |first3=Hideaki |last4=Weber |first4=Roy E. |last5=Fago |first5=Angela |last6=Cheviron |first6=Zachary A. |last7=Dudley |first7=Robert |last8=McGuire |first8=Jimmy A. |last9=Witt |first9=Christopher C. |last10=Storz |first10=Jay F. |display-authors=3 |date=2013-12-02 |title=Repeated elevational transitions in hemoglobin function during the evolution of Andean hummingbirds |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=110 |issue=51 |pages=20669–20674 |bibcode=2013PNAS..11020669P |doi=10.1073/pnas.1315456110 |issn=0027-8424 |pmc=3870697 |pmid=24297909 |doi-access=free}}{{Cite news |date=13 December 2013 |title=How do hummingbirds thrive in the Andes? |work=The Guardian |url=https://www.theguardian.com/science/grrlscientist/2013/dec/13/grrlscientist-hummingbirds-andes-hemoglobin-evolution |access-date=15 August 2022}}{{Cite journal |last1=Lim |first1=Marisa C.W. |last2=Witt |first2=Christopher C. |last3=Graham |first3=Catherine H. |last4=Dávalos |first4=Liliana M. |date=2019-05-22 |title=Parallel molecular evolution in pathways, genes, and sites in high-elevation hummingbirds revealed by comparative transcriptomics |journal=Genome Biology and Evolution |volume=11 |issue=6 |pages=1573–1585 |doi=10.1093/gbe/evz101 |issn=1759-6653 |pmc=6553505 |pmid=31114863}} In Andean hummingbirds living at high elevations, researchers found that the oxygen-carrying protein in blood {{Ndash}} [[hemoglobin]] {{Ndash}} had increased oxygen-[[Ligand (biochemistry)|binding affinity]], and that this adaptive effect likely resulted from evolutionary [[mutation]]s within the hemoglobin molecule via specific amino acid changes due to natural selection.{{Cite web |first=Deann|last=Gayman |date=2 December 2013 |title=New study reveals how hummingbirds evolved to fly at high altitude |url=https://news.unl.edu/newsrooms/today/article/new-study-reveals-how-hummingbirds-evolved-to-fly-at-high-altitude |access-date=15 August 2022 |publisher=Department of Communication and Marketing, University of Nebraska-Lincoln}} [248] => [249] => ===Adaptation to winter=== [250] => [251] => Anna's hummingbirds are the northernmost year-round residents of any hummingbird. Anna's hummingbirds were recorded in Alaska as early as 1971, and resident in the [[Pacific Northwest]] since the 1960s, particularly increasing as a year-round population during the early 21st century.{{cite journal | last1=Greig | first1=Emma I. | last2=Wood | first2=Eric M. | last3=Bonter | first3=David N. | title=Winter range expansion of a hummingbird is associated with urbanization and supplementary feeding | journal= Proceedings of the Royal Society B: Biological Sciences| volume=284 | issue=1852 | date=5 April 2017 | issn=0962-8452 | pmid=28381617 | pmc=5394677 | doi=10.1098/rspb.2017.0256 | page=20170256}}{{cite journal | last=Battey | first=C. J. | title=Ecological release of the Anna's hummingbird during a northern range expansion | journal=The American Naturalist| volume=194 | issue=3 | year=2019 | issn=0003-0147 | pmid=31553208 | doi=10.1086/704249 | pages=306–315| s2cid=164398193 | doi-access=free }} Scientists estimate that some Anna's hummingbirds overwinter and presumably breed at northern latitudes where food and shelter are available throughout winter, tolerating moderately cold winter temperatures. [252] => [253] => During cold temperatures, Anna's hummingbirds gradually gain weight during the day as they convert sugar to fat.{{cite journal |author1=Beuchat, C.A. |author2=Chaplin, S.B. |author3=Morton, M.L. |journal=Physiological Zoology|pages=280–295|volume=52|issue=3 |year=1979|title=Ambient temperature and the daily energetics of two species of hummingbirds, ''Calypte anna'' and ''Selasphorus rufus''|doi=10.1086/physzool.52.3.30155751 |s2cid=87185364 }}{{cite journal |last=Powers|first=D. R. |url=http://www.dpowerslab.com/wp-content/uploads/2011/09/PZ1991.pdf |jstor=30158211|title=Diurnal variation in mass, metabolic rate, and respiratory quotient in Anna's and Costa's hummingbirds|journal=Physiological Zoology|volume=64|issue= 3 |year=1991|pages=850–870|doi=10.1086/physzool.64.3.30158211|s2cid=55730100}} In addition, hummingbirds with inadequate stores of body fat or insufficient plumage are able to survive periods of subfreezing weather by lowering their metabolic rate and entering a state of [[torpor]].{{Cite journal |last1=Shankar |first1=Anusha |last2=Schroeder |first2=Rebecca J. |last3=Wethington |first3=Susan M. |last4=Graham |first4=Catherine H. |last5=Powers |first5=Donald R. |date=May 2020 |title=Hummingbird torpor in context: duration, more than temperature, is the key to nighttime energy savings |url=https://onlinelibrary.wiley.com/doi/10.1111/jav.02305 |journal=Journal of Avian Biology |language=en |volume=51 |issue=5 |pages=jav.02305 |doi=10.1111/jav.02305 |issn=0908-8857 |s2cid=216458501}} [254] => [255] => While their range was originally limited to the [[chaparral]] of California and [[Baja California Peninsula|Baja California]], it expanded northward to [[Oregon]], [[Washington (state)|Washington]], and [[British Columbia]], and east to [[Arizona]] over the 1960s to 1970s. This rapid expansion is attributed to the widespread planting of [[flora|non-native species]], such as [[eucalyptus]], as well as the use of urban [[bird feeders]], in combination with the species' natural tendency for extensive postbreeding [[biological dispersal|dispersal]].{{cite journal|url=https://birdsoftheworld.org/bow/species/annhum/1.0/introduction|vauthors=Clark CJ, Russell SM|date=2012|title=Anna's hummingbird (''Calypte anna'')|journal=The Birds of North America Online |publisher=The Birds of North America, Cornell University Laboratory of Ornithology|doi=10.2173/bna.226}} In the Pacific Northwest, the fastest growing populations occur in regions with breeding-season cold temperatures similar to those of its native range. Northward expansion of the Anna's hummingbird represents an [[ecological release]] associated with introduced plants, year-round nectar availability from feeders supplied by humans, milder winter temperatures associated with climate change, and acclimation of the species to a winter climate cooler than its native region. Although quantitative data are absent, it is likely that a sizable percentage of Anna's hummingbirds in the Pacific Northwest still do migrate south for winter, as of 2017. [256] => [257] => Anna's hummingbird is the official city bird of [[Vancouver, British Columbia]], Canada,{{cite web|url=https://vancouver.ca/parks-recreation-culture/official-city-bird.aspx|title=Official City Bird: Anna's Hummingbird|publisher=City of Vancouver|date=2019|access-date=6 November 2019}} and is a non-migrating resident of [[Seattle]] where it lives year-round through winter enduring extended periods of subfreezing temperatures, snow, and high winds.{{cite web |last1=Green|first1=Gregory A. |title=Anna's Hummingbird: Our winter hummingbird |url=https://www.birdwatchingdaily.com/news/species-profiles/annas-hummingbird-our-winter-hummingbird/# |publisher=BirdWatching |access-date=6 November 2019 |date=2 October 2018}} [258] => [259] => === Torpor === [260] => [261] => The metabolism of hummingbirds can slow at night or at any time when food is not readily available; the birds enter a deep-sleep state (known as torpor) to prevent energy reserves from falling to a critical level. One study of broad-tailed hummingbirds found that body weight decreased linearly throughout torpor at a rate of 0.04 g per hour. [262] => [263] => During nighttime torpor, [[body temperature]] in a Caribbean hummingbird was shown to fall from 40 to 18 °C,{{Cite journal |last1=Hainsworth |first1=F.R. |last2=Wolf |first2=L.L. |year=1970 |title=Regulation of oxygen consumption and body temperature during torpor in a hummingbird, Eulampis jugularis |journal=Science |volume=168 |issue=3929 |pages=368–369 |bibcode=1970Sci...168..368R |doi=10.1126/science.168.3929.368 |pmid=5435893 |s2cid=30793291}} with heart and [[breathing rate]]s slowing dramatically (heart rate of roughly 50 to 180 bpm from its daytime rate of higher than 1000 bpm).{{Cite journal |last=Hiebert |first=S.M. |year=1992 |title=Time-dependent thresholds for torpor initiation in the rufous hummingbird (''Selasphorus rufus'') |journal=Journal of Comparative Physiology B |volume=162 |issue=3 |pages=249–255 |doi=10.1007/bf00357531 |pmid=1613163 |s2cid=24688360}} Recordings from a ''[[Metallura phoebe]]'' hummingbird in noctural torpor at around {{Convert|3800|m|ft}} in the Andes mountains showed that body temperature fell to 3.3 °C (38 °F), the lowest known level for a bird or non-hibernating mammal.{{Cite journal |last1=Wolf |first1=Blair O. |last2=McKechnie |first2=Andrew E. |last3=Schmitt |first3=C. Jonathan |last4=Czenze |first4=Zenon J. |last5=Johnson |first5=Andrew B. |last6=Witt |first6=Christopher C. |year=2020 |title=Extreme and variable torpor among high-elevation Andean hummingbird species |journal= Biology Letters|volume=16 |issue=9 |page=20200428 |doi=10.1098/rsbl.2020.0428 |issn=1744-9561 |pmc=7532710 |pmid=32898456}}{{Cite news |last=Greenwood |first=Veronique |date=2020-09-08 |title=These hummingbirds take extreme naps. Some may even hibernate. |language=en-US |work=The New York Times |url=https://www.nytimes.com/2020/09/08/science/hummingbirds-torpor-hibernation.html |access-date=2020-09-09 |issn=0362-4331}} During cold nights at altitude, hummingbirds were in torpor for 2–13 hours depending on species, with cooling occurring at the rate of 0.6 °C per minute and rewarming at 1–1.5 °C per minute. High-altitude Andean hummingbirds also lost body weight in negative proportion to how long the birds were in torpor, losing about 6% of weight each night. [264] => [265] => During torpor, to prevent [[dehydration]], the [[glomerular filtration rate|kidney function]] declines, preserving needed compounds, such as glucose, water, and nutrients. The circulating [[hormone]], [[corticosterone]], is one signal that arouses a hummingbird from torpor.{{Cite journal |last1=Hiebert |first1=S.M. |last2=Salvante |first2=K.G. |last3=Ramenofsky |first3=M. |last4=Wingfield |first4=J.C. |year=2000 |title=Corticosterone and nocturnal torpor in the rufous hummingbird (''Selasphorus rufus'') |journal=General and Comparative Endocrinology |volume=120 |issue=2 |pages=220–234 |doi=10.1006/gcen.2000.7555 |pmid=11078633}} [266] => [267] => Use and duration of torpor vary among hummingbird species and are affected by whether a dominant bird defends territory, with nonterritorial subordinate birds having longer periods of torpor.{{Cite journal |last1=Powers |first1=D.R. |last2=Brown |first2=A.R. |last3=Van Hook |first3=J.A. |year=2003 |title=Influence of normal daytime fat deposition on laboratory measurements of torpor use in territorial versus nonterritorial hummingbirds |url=https://digitalcommons.georgefox.edu/cgi/viewcontent.cgi?article=1025&context=bio_fac |journal=Physiological and Biochemical Zoology |volume=76 |issue=3 |pages=389–397 |doi=10.1086/374286 |pmid=12905125 |s2cid=6475160}} A hummingbird with a higher fat percentage will be less likely to enter a state of torpor compared to one with less fat, as a bird can use the energy from its fat stores. Torpor in hummingbirds appears to be unrelated to nighttime temperature, as it occurs across a wide temperature range, with energy savings of such deep sleep being more related to the [[photoperiod]] and duration of torpor. [268] => [269] => === Lifespan === [270] => [271] => Hummingbirds have unusually long lifespans for organisms with such rapid metabolisms. Though many die during their first year of life, especially in the vulnerable period between hatching and [[fledging]], those that survive may occasionally live a decade or more.{{Cite web |date=2010 |title=The hummingbird project of British Columbia |url=http://rpbo.org/hummingbirds.php |access-date=25 June 2016 |publisher=Rocky Point Bird Observatory, Vancouver Island, British Columbia}} Among the better-known North American species, the typical lifespan is probably 3 to 5 years. For comparison, the smaller [[shrew]]s, among the smallest of all mammals, seldom live longer than 2 years.{{Cite book |last=Churchfield |first=Sara |title=The natural history of shrews |publisher=Cornell University Press |year=1990 |isbn=978-0-8014-2595-0 |pages=35–37}} The longest recorded lifespan in the wild relates to a female broad-tailed hummingbird that was banded as an adult at least one year old, then recaptured 11 years later, making her at least 12 years old.{{Cite web |title=Longevity Records Of North American Birds |url=https://www.pwrc.usgs.gov/BBL/longevity/Longevity_main.cfm |access-date=26 January 2021 |publisher=United States Geological Survey}} Other longevity records for banded hummingbirds include an estimated minimum age of 10 years 1 month for a female black-chinned hummingbird similar in size to the broad-tailed hummingbird, and at least 11 years 2 months for a much larger [[buff-bellied hummingbird]].{{cite web |url=http://www.pwrc.usgs.gov/BBL/homepage/long3930.cfm |title=Longevity Records AOU Numbers 3930–4920 |publisher=Patuxent Wildlife Research Center, Bird Banding Laboratory |date=2009-08-31 |accessdate=2009-09-27}} [272] => [273] => ==Natural enemies== [274] => ===Predators=== [275] => [276] => [[Mantis|Praying mantises]] have been observed as predators of hummingbirds.{{Cite journal |last=Fisher |first=R. Jr. |date=1994 |title=Praying mantis catches and eats hummingbird |journal=Birding |volume=26 |pages=376}}{{Cite journal |last=Lorenz |first=S. |date=2007 |title=Carolina mantid (''Stagmomantis carolina'') captures and feeds on a broad-tailed hummingbird (''Selasphorus platycercus'') |journal=Bulletin of the Texas Ornithological Society |volume=40 |pages=37–38}}{{Cite journal |last1=Nyffeler |first1=Martin |last2=Maxwell |first2=Michael R. |last3=Remsen |first3=J.V. |year=2017 |title=Bird predation by praying mantises: A global perspective |url=https://bioone.org/journals/the-wilson-journal-of-ornithology/volume-129/issue-2/16-100.1/Bird-Predation-By-Praying-Mantises-A-Global-Perspective/10.1676/16-100.1.full |journal=The Wilson Journal of Ornithology |volume=129 |issue=2 |pages=331–344 |doi=10.1676/16-100.1 |issn=1559-4491 |s2cid=90832425}} Other predators include [[Cat|domestic cats]], [[dragonfly|dragonflies]], [[frog]]s, [[orb-weaver spider]]s, and other birds, such as the [[roadrunner]].{{Cite web |first=Sharon |last=Stiteler |date=29 October 2015 |title=Which animals prey on hummingbirds? |url=https://www.audubon.org/news/which-animals-prey-hummingbirds |access-date=4 November 2021 |publisher=National Audubon Society}} [277] => [278] => ===Parasites=== [279] => Hummingbirds host a highly specialized lice fauna. Two genera of [[Ricinidae|Ricinid]] lice, [[Trochiloecetes]] and [[Trochiliphagus]], are specialized on them, often infesting 5–15% of their populations. In contrast, two genera of [[Menoponidae|Menoponid]] lice, [[Myrsidea]] and [[Leremenopon]]{{clarify|date=March 2024}}, are extremely rare on them.{{cite journal|last1=Oniki-Willis|first1=Yoshika|last2=Willis|first2=Edwin O|last3=Lopes|first3=Leonardo E|last4=Rozsa|first4=Lajos|title= Museum-based research on the lice (Insecta: Phthiraptera) infestations of hummingbirds (Aves: Trochilidae) – prevalence, genus richness, and parasite associations |journal= Diversity|volume=15|year=2023|pages=54|doi= 10.3390/d15010054|doi-access=free }}{{cite journal|last1=Sychra|first1=Oldřich|display-authors=etal|title= Multivariate study of lice (Insecta: Psocodea: Phthiraptera) assemblages hosted by hummingbirds (Aves: Trochilidae)|journal=Parasitology |volume=151|year=2024|issue=2 |pages=191–199|doi=10.1017/S0031182023001294|doi-access=free |pmid=38116659 |pmc=10941040}} [280] => [281] => == Reproduction == [282] => [[File:Trochilidae - Hummingbird.webm|thumb|Video of a hummingbird building a nest]] [283] => [284] => Male hummingbirds do not take part in nesting.{{Cite journal |last1=Oniki |first1=Y |last2=Willis |first2=E.O. |year=2000 |title=Nesting behavior of the swallow-tailed hummingbird, ''Eupetomena macroura'' (Trochilidae, Aves) |journal=Brazilian Journal of Biology |volume=60 |issue=4 |pages=655–662 |doi=10.1590/s0034-71082000000400016 |pmid=11241965 |doi-access=free|hdl=11449/28969 |hdl-access=free }} Most species build a cup-shaped nest on the branch of a tree or shrub.{{Cite web |date=2016 |title=Hummingbird nesting |url=http://www.learner.org/jnorth/humm/spring2016/c051316_nest.html |url-status=dead |archive-url=https://web.archive.org/web/20170202001143/http://www.learner.org/jnorth/humm/spring2016/c051316_nest.html |archive-date=2 February 2017 |access-date=12 May 2016 |publisher=Public Broadcasting System – Nature; from Learner.org, Journey North |format=video}} The nest varies in size relative to the particular species – from smaller than half a [[walnut]] shell to several centimeters in diameter. [285] => [286] => Many hummingbird species use [[spider silk]] and lichen to bind the nest material together and secure the structure.{{Cite web |date=2014 |title=Hummingbird Q&A: Nest and eggs |url=http://www.rubythroat.org/questionsnesteggs01.html |access-date=21 June 2014 |publisher=Operation Rubythroat: The Hummingbird Project, Hilton Pond Center for Piedmont Natural History}} The unique properties of the silk allow the nest to expand as the young hummingbirds grow. Two white eggs are laid, which despite being the smallest of all bird eggs, are large relative to the adult hummingbird's size. [[Egg incubation|Incubation]] lasts 14 to 23 days, depending on the species, ambient temperature, and female attentiveness to the nest. The mother feeds her nestlings on small [[arthropod]]s and nectar by inserting her bill into the open mouth of a [[Nestling#Parental care and fledging|nestling]], and then regurgitating the food into its [[Crop (anatomy)|crop]]. Hummingbirds stay in the nest for 18–22 days, after which they leave the nest to forage on their own, although the mother bird may continue feeding them for another 25 days.{{Cite web |last=Mohrman |first=Eric |date=22 November 2019 |title=How do hummingbirds mate? |url=https://sciencing.com/hummingbirds-mate-4566850.html |access-date=8 February 2020 |publisher=Sciencing, Leaf Group Media}} [287] => [288] => ==Flight == [289] => [[File:Hummingbird Aerodynamics of flight.jpg|thumb|left|A female ruby-throated hummingbird hovering in mid-air]] [290] => [291] => Hummingbird flight has been studied intensively from an aerodynamic perspective using wind tunnels and high-speed [[video camera]]s. Two studies of rufous or Anna's hummingbirds in a wind tunnel used [[particle image velocimetry]] techniques to investigate the lift generated on the bird's upstroke and downstroke.{{Cite journal |last1=Warrick |first1=Douglas R. |last2=Tobalske |first2=Bret W. |last3=Powers |first3=Donald R. |year=2005 |title=Aerodynamics of the hovering hummingbird |url=https://digitalcommons.georgefox.edu/cgi/viewcontent.cgi?article=1033&context=bio_fac |journal=Nature |volume=435 |issue=7045 |pages=1094–097 |bibcode=2005Natur.435.1094W |doi=10.1038/nature03647 |pmid=15973407 |s2cid=4427424}}{{Cite journal |last1=Sapir |first1=N. |last2=Dudley |first2=R. |year=2012 |title=Backward flight in hummingbirds employs unique kinematic adjustments and entails low metabolic cost |journal=Journal of Experimental Biology |volume=215 |issue=20 |pages=3603–611 |doi=10.1242/jeb.073114 |pmid=23014570 |doi-access=free}} The birds produced 75% of their weight support during the downstroke and 25% during the upstroke, with the wings making a "figure 8" motion.{{Cite journal|last1=Tobalske |first1=Bret W. |last2=Warrick |first2=Douglas R. |last3=Clark |first3=Christopher J. |last4=Powers |first4=Donald R. |last5=Hedrick |first5=Tyson L. |last6=Hyder |first6=Gabriel A. |last7=Biewener |first7=Andrew A. |year=2007 |title=Three-dimensional kinematics of hummingbird flight |journal=J Exp Biol |volume=210 |issue=13 |pages=2368–382 |doi=10.1242/jeb.005686 |pmid=17575042 |doi-access=free}} [292] => [293] => [[File:Hummingbird wake Pengo.svg|thumb|upright=0.7|Hummingbirds generate a trail of wake [[Vortex|vortices]] under each wing while hovering.{{cite web |author1=University of California - Riverside |title=Study shows hovering hummingbirds generate two trails of vortices under their wings, challenging one-vortex consensus |url=https://phys.org/news/2013-02-hummingbirds-trails-vortices-wings-one-vortex.html |publisher=Phys.org |access-date=8 March 2023 |date=25 February 2013}}{{cite journal |last1=Pournazeri |first1=Sam |last2=Segre |first2=Paolo S. |last3=Princevac |first3=Marko |last4=Altshuler |first4=Douglas L. |title=Hummingbirds generate bilateral vortex loops during hovering: evidence from flow visualization |journal=Experiments in Fluids |volume=54 |issue=1 |date=2012-12-25 |issn=0723-4864 |doi=10.1007/s00348-012-1439-5 |page=1439|s2cid=253853891 |url= https://link.springer.com/article/10.1007/s00348-012-1439-5}}]] [294] => [295] => Many earlier studies had assumed that [[lift (force)|lift]] was generated equally during the two phases of the wingbeat cycle, as is the case of insects of a similar size. This finding shows that hummingbird [[Levitation (physics)|hovering]] is similar to, but distinct from, that of hovering insects such as the [[hawk moth]]. Further studies using [[electromyography]] in hovering rufous hummingbirds showed that [[muscle strain]] in the pectoralis major (principal downstroke muscle) was the lowest yet recorded in a flying bird, and the primary upstroke muscle (supracoracoideus) is proportionately larger than in other bird species.{{Cite journal |last1=Tobalske |first1=B.W. |last2=Biewener |first2=A.A. |last3=Warrick |first3=D.R. |last4=Hedrick |first4=T.L. |last5=Powers |first5=D.R. |year=2010 |title=Effects of flight speed upon muscle activity in hummingbirds |journal=Journal of Experimental Biology |volume=213 |issue=14 |pages=2515–523 |doi=10.1242/jeb.043844 |pmid=20581281 |doi-access=free}} Presumably due to rapid wingbeats for flight and hovering, hummingbird wings have adapted to perform without an [[alula]].{{Cite book |last=Videler|first= J.J.|url=https://books.google.com/books?id=5Xr9NZdgzP0C&q=hummingbird+alula+digit+is+reduced+and+immobile&pg=PA34 |title=Avian Flight |date=2005 |publisher=Oxford University Press, Ornithology Series |isbn=978-0-19-856603-8 |page=34}} [296] => [297] => The giant hummingbird's wings beat as few as 12 times per second,{{Cite journal |last1=Fernández |first1=M.J. |last2=Dudley |first2=R. |last3=Bozinovic |first3=F. |year=2011 |title=Comparative energetics of the giant hummingbird (Patagona gigas) |journal=Physiological and Biochemical Zoology |volume=84 |issue=3 |pages=333–340 |doi=10.1086/660084 |pmid=21527824 |s2cid=31616893}} and the wings of typical hummingbirds beat up to 80 times per second.{{Cite news |last=Gill |first=V. |date=30 July 2014 |title=Hummingbirds edge out helicopters in hover contest |work=BBC News |url=https://www.bbc.com/news/28563737 |access-date=1 Sep 2014}} As air density decreases, for example, at higher altitudes, the amount of power a hummingbird must use to hover increases. Hummingbird species adapted for life at higher altitudes, therefore, have larger wings to help offset these negative effects of low air density on lift generation.{{Cite journal |last1=Feinsinger |first1=Peter |last2=Colwell |first2=Robert K. |last3=Terborgh |first3=John |last4=Chaplin |first4=Susan Budd |date=1979 |title=Elevation and the Morphology, Flight Energetics, and Foraging Ecology of Tropical Hummingbirds |journal=The American Naturalist |volume=113 |issue=4 |pages=481–497 |doi=10.1086/283408 |issn=0003-0147 |s2cid=85317341}} [298] => [299] => A slow-motion video has shown how the hummingbirds deal with rain when they are flying. To remove the water from their heads, they shake their heads and bodies, similar to a dog shaking, to shed water.{{Cite news |last=Morelle|first=R. |author-link=Rebecca Morelle |date=8 November 2011 |title=Hummingbirds shake their heads to deal with rain |work=BBC News |url=https://www.bbc.com/news/science-environment-15620024 |access-date=22 March 2014}} Further, when raindrops collectively may weigh as much as 38% of the bird's body weight, hummingbirds shift their bodies and tails horizontally, beat their wings faster, and reduce their wings' angle of motion when flying in heavy rain.{{Cite news |last=St. Fleur|first= N. |date=20 July 2012 |title=Hummingbird rain trick: New study shows tiny birds alter posture in storms |work=Huffington Post |format=video |url=http://www.huffingtonpost.com/2012/07/19/hummingbird-rain-video_n_1685752.html |access-date=22 March 2014}} [300] => [301] => === Wingbeats and flight stability === [302] => [[File:Hummingbird feeding closeup 2000fps.webm|thumb|Slow-motion video of hummingbirds feeding]] [303] => [304] => The highest recorded wingbeat rate for hummingbirds during hovering is 99.1 per second, as measured for male woodstars (''Chaetocercus sp.'').{{Cite journal |last1=Wilcox |first1=Sean |last2=Clark |first2=Christopher |year=2022 |title=Sexual selection for flight performance in hummingbirds |url=https://academic.oup.com/beheco/article/33/6/1093/6686581 |journal=Behavioral Ecology |volume=33 |issue=6 |pages=1093–1106|doi=10.1093/beheco/arac075 }} Males in the genus ''[[Chaetocercus]]'' have been recorded above 100 beats per second during courtship displays. The number of beats per second increases above "normal" hovering while flying during courtship displays (up to 90 per second for the calliope hummingbird, ''Selasphorus calliope''); a wingbeat rate 40% higher than its typical hovering rate.{{Cite journal |last=Clark |first=C.J. |year=2011 |title=Wing, tail, and vocal contributions to the complex acoustic signals of courting Calliope hummingbirds |journal=Current Zool. |volume=57 |issue=2 |pages=187–196 |doi=10.1093/czoolo/57.2.187 |doi-access=free}} [305] => [306] => During turbulent airflow conditions created experimentally in a [[wind tunnel]], hummingbirds exhibit stable head positions and orientation when they [[Bird flight#Hovering|hover]] at a feeder.{{Cite journal |last1=Ravi |first1=Sridhar |last2=Crall |first2=James D. |last3=McNeilly |first3=Lucas |last4=Gagliardi |first4=Susan F. |last5=Biewener |first5=Andrew A. |last6=Combes |first6=Stacey A.|year=2015 |title=Hummingbird flight stability and control in freestream turbulent winds |journal=J Exp Biol |volume=218 |issue=Pt 9 |pages=1444–452 |doi=10.1242/jeb.114553 |pmid=25767146 |doi-access=free}} When wind gusts from the side, hummingbirds compensate by increasing wing-stroke [[amplitude]] and stroke plane angle and by varying these parameters asymmetrically between the wings and from one stroke to the next. They also vary the orientation and enlarge the collective [[surface area]] of their tail feathers into the shape of a [[hand fan|fan]]. While hovering, the [[visual system]] of a hummingbird is able to separate apparent motion caused by the movement of the hummingbird itself from motions caused by external sources, such as an approaching predator. In natural settings full of highly complex background motion, hummingbirds are able to precisely hover in place by rapid coordination of vision with body position. [307] => [308] => == Feather sounds == [309] => [310] => === Courtship dives === [311] => [312] => When courting, the male Anna's hummingbird ascends some {{Convert|35|m|abbr=on}} above a female, before diving at a speed of {{Convert|27|m/s|abbr=on}}, equal to 385 body lengths/sec – producing a high-pitched sound near the female at the [[nadir]] of the dive.{{Cite journal |last=Clark |first=C.J. |year=2009 |title=Courtship dives of Anna's hummingbird offer insights into flight performance limits |journal=Proceedings of the Royal Society B: Biological Sciences |volume=276 |issue=1670 |pages=3047–052 |doi=10.1098/rspb.2009.0508 |pmc=2817121 |pmid=19515669}} This downward acceleration during a dive is the highest reported for any vertebrate undergoing a voluntary aerial maneuver; in addition to acceleration, the speed relative to body length is the highest known for any vertebrate. For instance, it is about twice the diving speed of [[peregrine falcon]]s in pursuit of prey. At maximum descent speed, about 10 g of gravitational force occur in the courting hummingbird during a dive (Note: G-force is generated as the bird pulls out of the dive).{{efn|By comparison to humans, this is a G-force acceleration well beyond the threshold of causing near loss of [[consciousness]] (occurring at about +5 Gz) in [[fighter pilot]]s during operation of a [[fixed-wing aircraft]] in a high-speed [[banked turn]].{{Cite book |last1=Akparibo |first1=Issaka Y. |url=https://www.ncbi.nlm.nih.gov/books/NBK430768 |title=Aerospace, gravitational effects, high performance |last2=Anderson |first2=Jackie |last3=Chumbley |first3=Eric |date=2020-09-07 |publisher=National Center for Biotechnology Information, US National Institute of Medicine |chapter=Aerospace Gravitational Effects |pmid=28613519}}}} [313] => [314] => The outer tail feathers of male Anna's (''Calypte anna'') and ''Selasphorus'' hummingbirds (e.g., Allen's, calliope) vibrate during courtship display dives and produce an audible chirp caused by aeroelastic flutter.{{Cite journal |last1=Clark |first1=C. J. |last2=Feo |first2=T.J. |year=2008 |title=The Anna's hummingbird chirps with its tail: A new mechanism of sonation in birds |journal=Proceedings of the Royal Society B: Biological Sciences |volume=275 |issue=1637 |pages=955–962 |doi=10.1098/rspb.2007.1619 |pmc=2599939 |pmid=18230592}}{{Cite journal |last=Clark|first= C.J. |year=2014 |title=Harmonic hopping, and both punctuated and gradual evolution of acoustic characters in Selasphorus hummingbird tail-feathers |journal=PLOS ONE |volume=9 |issue=4 |page=e93829 |bibcode=2014PLoSO...993829C |doi=10.1371/journal.pone.0093829 |pmc=3983109 |pmid=24722049 |doi-access=free}} Hummingbirds cannot make the courtship dive sound when missing their outer tail feathers, and those same feathers could produce the dive sound in a wind tunnel. The bird can sing at the same frequency as the tail-feather chirp, but its small syrinx is not capable of the same volume.{{Cite journal |last1=Clark |first1=C. J. |last2=Feo |first2=T. J. |year=2010 |title=Why do Calypte hummingbirds "sing" with both their tail and their syrinx? An apparent example of sexual sensory bias |journal=The American Naturalist |volume=175 |issue=1 |pages=27–37 |doi=10.1086/648560 |pmid=19916787 |s2cid=29680714}} The sound is caused by the aerodynamics of rapid air flow past tail feathers, causing them to [[aeroelasticity|flutter]] in a [[vibration]], which produces the high-pitched sound of a courtship dive.{{Cite journal |last1=Clark |first1=C.J. |last2=Elias |first2=D.O. |last3=Prum |first3=R.O. |year=2013 |title=Hummingbird feather sounds are produced by aeroelastic flutter, not vortex-induced vibration |journal=Journal of Experimental Biology |volume=216 |issue=18 |pages=3395–403 |doi=10.1242/jeb.080317 |pmid=23737562 |doi-access=free}} [315] => [316] => Many other species of hummingbirds also produce sounds with their wings or tails while flying, hovering, or diving, including the wings of the calliope hummingbird,{{Cite journal |last=Clark |first=C.J. |year=2011 |title=Wing, tail, and vocal contributions to the complex acoustic signals of courting Calliope hummingbirds |url=http://www.actazool.org/temp/%7BACDC40CC-89E0-41E6-A4B2-7C7FB6734F1E%7D.pdf |url-status=dead |journal=Current Zoology |volume=57 |issue=2 |pages=187–196 |doi=10.1093/czoolo/57.2.187 |archive-url=https://web.archive.org/web/20150716160821/http://www.actazool.org/temp/%7BACDC40CC-89E0-41E6-A4B2-7C7FB6734F1E%7D.pdf |archive-date=2015-07-16 |access-date=2015-05-31 |doi-access=free}} broad-tailed hummingbird, rufous hummingbird, Allen's hummingbird, and the [[streamertail]] species, as well as the tail of the Costa's hummingbird and the black-chinned hummingbird, and a number of related species.{{Cite web |last=Kovacevic |first=M.|date=2008-01-30 |title=Hummingbird sings with its tail feathers |url=http://www.cosmosmagazine.com/news/1829/hummingbird-sings-with-its-tail-feathers |url-status=dead |archive-url=https://web.archive.org/web/20120503042604/http://www.cosmosmagazine.com/news/1829/hummingbird-sings-with-its-tail-feathers |archive-date=2012-05-03 |access-date=2013-07-13 |publisher=Cosmos Magazine}} The [[harmonic]]s of sounds during courtship dives vary across species of hummingbirds. [317] => [318] => === Wing feather trill === [319] => [320] => Male rufous and broad-tailed hummingbirds (genus ''[[Selasphorus]]'') have a distinctive wing feature during normal flight that sounds like jingling or a buzzing shrill whistle {{ndash}} a trill.{{Cite journal |last1=Miller |first1=Sarah J. |last2=Inouye |first2=David W. |date=1983 |title=Roles of the Wing Whistle in the Territorial Behaviour of Male Broad-tailed Hummingbirds (''Selasphorus platycercus'') |url=http://www.hummingbirds.net/miller1983.html |journal=Animal Behaviour |volume=31 |issue=3 |pages=689–700 |doi=10.1016/S0003-3472(83)80224-3 |access-date=13 July 2014 |via=hummingbirds.net |s2cid=53160649}} The trill arises from air rushing through slots created by the tapered tips of the ninth and tenth primary wing feathers, creating a sound loud enough to be detected by female or competitive male hummingbirds and researchers up to 100 m away. [321] => [322] => Behaviorally, the trill serves several purposes: It announces the sex and presence of a male bird; it provides audible aggressive defense of a feeding territory and an intrusion tactic; it enhances communication of a threat; and it favors mate attraction and courtship. [323] => [324] => == Migration == [325] => [326] => Relatively few hummingbirds migrate as a percentage of the total number of species; of the roughly 366 known hummingbird species, only 12–15 species migrate annually, particularly those in North America.{{cite web |last1=Lowe|first1=Joe |title=Do hummingbirds migrate? |url=https://abcbirds.org/blog/do-hummingbirds-migrate/ |publisher=American Bird Conservancy |access-date=8 March 2023 |date=12 September 2019}} Most hummingbirds live in the [[Amazonia]]-Central America [[tropical rainforest]] belt, where seasonal temperature changes and food sources are relatively constant, obviating the need to migrate.{{cite web |last1=Godshalk |first1=Katrina |title=Hummingbird migration |url=https://www.highcountrygardens.com/gardening/best-plants-hummingbird-migration |website=High Country Gardens |access-date=16 January 2023}} As the smallest living birds, hummingbirds are relatively limited at conserving heat energy, and are generally unable to maintain a presence in higher latitudes during winter months, unless the specific location has a large food supply throughout the year, particularly access to flower nectar.{{cite journal |last1=López-Segoviano |first1=Gabriel |last2=Arenas-Navarro |first2=Maribel |last3=Vega |first3=Ernesto |last4=Arizmendi |first4=Maria del Coro |title=Hummingbird migration and flowering synchrony in the temperate forests of northwestern Mexico |journal=PeerJ |volume=6 |issue= |pages=e5131 |date=2018 |pmid=30002968 |pmc=6037137 |doi=10.7717/peerj.5131 |doi-access=free }} Other migration factors are seasonal fluctuation of food, climate, competition for resources, predators, and inherent signals. [327] => [328] => Most North American hummingbirds migrate southward in fall to spend winter in Mexico, the Caribbean Islands, or Central America.{{Cite web |date=2023 |title=Hummingbird migration |url=https://www.hummingbirdcentral.com/hummingbird-migration.htm |access-date=28 August 2018 |publisher=Hummingbird Central}} A few species are year-round residents of [[Florida]], California, and the southwestern desert regions of the US. Among these are Anna's hummingbird, a common resident from southern Arizona and inland California, and the [[buff-bellied hummingbird]], a winter resident from Florida across the Gulf Coast to [[South Texas]]. Ruby-throated hummingbirds are common along the [[Atlantic flyway]], and migrate in summer from as far north as [[Atlantic Canada]], returning to Mexico, South America, southern Texas, and Florida to winter. During winter in southern [[Louisiana]], black-chinned, buff-bellied, calliope, Allen's, Anna's, ruby-throated, rufous, broad-tailed, and broad-billed hummingbirds are present. [329] => [330] => The rufous hummingbird breeds farther north than any other species of hummingbird, spending summers along coastal British Columbia and Alaska, and wintering in the southwestern United States and Mexico, with some distributed along the coasts of the subtropical Gulf of Mexico and Florida. By migrating in spring as far north as the [[Yukon]] or southern Alaska,{{Cite web |date=2023 |title=Rufous hummingbird |url=http://www.allaboutbirds.org/guide/Rufous_Hummingbird/lifehistory |access-date=29 April 2023 |publisher=Cornell University Laboratory of Ornithology}} the rufous hummingbird migrates more extensively and nests farther north than any other hummingbird species, and must tolerate occasional temperatures below freezing in its breeding territory. This cold hardiness enables it to survive temperatures below freezing, provided that adequate shelter and food are available. [331] => [332] => As calculated by [[displacement (vector)|displacement]] of body size, the rufous hummingbird makes perhaps the longest migratory journey of any bird in the world. At just over {{convert|3|in|cm}} long, rufous hummingbirds travel {{convert|3900|mi}} one-way from Alaska to Mexico in late summer, a distance equal to 78,470,000 body lengths, then make the return journey in the following spring. By comparison, the {{convert|13|in|cm}}-long [[Arctic tern]] makes a one-way flight of about {{convert|18,000|km}}, or 51,430,000 body lengths, just 65% of the body displacement during migration by rufous hummingbirds. [333] => [334] => The northward migration of rufous hummingbirds occurs along the [[Pacific flyway]],{{Cite web |title=Map of rufous hummingbird migration, Spring 2023 |url=https://maps.journeynorth.org/map/?map=hummingbird-rufous-first&year=2023|date=29 April 2023 |access-date=29 April 2023 |publisher=Journey North, Annenberg Learner}} and may be time-coordinated with flower and tree-leaf emergence in early spring, and also with availability of insects as food. Arrival at breeding grounds before nectar availability from mature flowers may jeopardize breeding opportunities.{{Cite journal |last1=McKinney |first1=A.M. |last2=Caradonna |first2=P.J. |last3=Inouye |first3=D.W. |last4=Barr |first4=B |last5=Bertelsen |first5=C.D. |last6=Waser |first6=N.M. |year=2012 |title=Asynchronous changes in phenology of migrating broad-tailed hummingbirds and their early-season nectar resources |url=https://pure.au.dk/ws/files/83236748/McKinney_et_al._2012_with_cover.pdf |journal=Ecology |volume=93 |issue=9 |pages=1987–993 |doi=10.1890/12-0255.1 |pmid=23094369}} [335] => [336] => == Feeding == [337] => [[File:Humming birds feeding at 1500fps.webm|thumb|Hummingbirds feeding; video recorded at 1,500 frames per second]] [338] => [[File:Hummingbird.ogg|thumb|Hummingbird visiting flowers in [[Copiapó, Chile]]: The apparent slow movement of hummingbird wings is a result of the [[stroboscopic effect]].]] [339] => [340] => All hummingbirds are overwhelmingly [[nectarivorous]],{{cite book |last1=del Hoyo |first1=Josep |last2=Andrew |first2=Elliott |last3=Sargatal |first3=Jordi |title=Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds |date=1999 |publisher=Lynx Edicions |location=Barcelona |isbn=84-87334-25-3 |pages=475–680}}{{cite journal | last=Stiles | first=F. Gary | title=Behavioral, Ecological and Morphological Correlates of Foraging for Arthropods by the Hummingbirds of a Tropical Wet Forest | journal=The Condor | publisher=Oxford University Press (OUP) | volume=97 | issue=4 | year=1995 | url=https://academic.oup.com/condor/article-abstract/97/4/853/5126159 | doi=10.2307/1369527 | pages=853–878| jstor=1369527 }}{{cite journal | last1=Abrahamczyk | first1=Stefan | last2=Kessler | first2=Michael | title=Hummingbird diversity, food niche characters, and assemblage composition along a latitudinal precipitation gradient in the Bolivian lowlands | journal=Journal of Ornithology | publisher=Springer Science and Business Media LLC | volume=151 | issue=3 | date=12 February 2010 | url=https://link.springer.com/article/10.1007/s10336-010-0496-x | doi=10.1007/s10336-010-0496-x | pages=615–625| s2cid=25235280 }}{{cite journal | last=PYKE | first=GRAHAM H. | title=The foraging behaviour of Australian honeyeaters: a review and some comparisons with hummingbirds | journal=Austral Ecology | publisher=Wiley | volume=5 | issue=4 | year=1980 | url=https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1442-9993.1980.tb01258.x | doi=10.1111/j.1442-9993.1980.tb01258.x | pages=343–369| bibcode=1980AusEc...5..343P }} being by far the most specialized such feeders among birds, as well as the only birds for whom nectar typically comprises the vast majority of energy intake. Hummingbirds exhibit numerous and extensive adaptations to nectarivory, including long, probing bills and tongues which rapidly take up fluids. Hummingbirds also possess the most sophisticated [[Bird flight#Hovering|hovering]] flight of all birds, a necessity for rapidly visiting many flowers without perching. Their [[intestines]] are capable of extracting over 99% of the glucose from nectar feedings within minutes, owing to high densities of glucose transporters (the highest known among vertebrates). [341] => [342] => As among the most important vertebrate [[pollinator]]s, hummingbirds have [[Coevolution#Birds and bird-pollinated flowers|coevolved]] in complex ways with flowering plants; thousands of [[New World]] species have evolved to be pollinated exclusively by hummingbirds, even barring access to [[insect]] pollinators. In some plants these mechanisms, which include highly modified [[Corolla (flower)|corolla]]s, even render their [[nectaries]] inaccessible to all but certain hummingbirds, i.e., those possessing appropriate beak morphologies (although some hummingbirds rob nectar to overcome this). Bird-pollinated plants (also termed "ornithophilous") were formerly thought to exemplify very close mutualisms, with specific flowering plants coevolving alongside specific hummingbirds in mutualistic pairings. Both ornithophilous plants and hummingbirds are now known to not be nearly selective enough for this to be true.{{cite journal | last1=Spence | first1=Austin R | last2=Wilson Rankin | first2=Erin E | last3=Tingley | first3=Morgan W | title=DNA metabarcoding reveals broadly overlapping diets in three sympatric North American hummingbirds | journal=Ornithology | publisher=Oxford University Press (OUP) | volume=139 | issue=1 | date=3 December 2021 | url=https://academic.oup.com/auk/article/139/1/ukab074/6429138 | doi=10.1093/ornithology/ukab074 | page=| doi-access=free }} Less accessible ornithophiles (for example, those requiring long bills) still rely on multiple hummingbird species for pollination. More importantly, hummingbirds tend not to be especially selective nectar-feeders, even regularly visiting non-ornithophilous plants, as well as ornithophiles which appear poorly suited for feeding by their species. Feeding efficiency is optimized, however, when birds feed on flowers better suited to their bill morphologies. [343] => [344] => Although they may not be one-to-one, there are still marked overall preferences for certain genera, families, and orders of flowering plants by hummingbirds in general, as well as by certain species of hummingbird. Flowers which are attractive to hummingbirds are often colorful (particularly red), open diurnally, and produce nectar with a high sucrose content; in ornithophilous plants, the corollas are often elongated and tubular, and they may be scentless (several of these are adaptations discouraging insect visitation). Some common genera consumed by many species include ''[[Castilleja]]'', ''[[Centropogon]]'', ''[[Costus]]'', ''[[Delphinium]]'', ''[[Heliconia]]'', ''[[Hibiscus]]'', ''[[Inga]]'', and ''[[Mimulus]]''; some of these are primarily insect-pollinated. Three Californian species were found to feed from 62 plant families in 30 orders, with the most frequently occurring orders being [[Apiales]], [[Fabales]], [[Lamiales]], and [[Rosales]]. A hummingbird may have to visit one or two thousand flowers daily to meet energy demands.{{cite journal | last1=Toledo | first1=MCB. | last2=Moreira | first2=DM. | title=Analysis of the feeding habits of the swallow-tailed hummingbird, Eupetomena macroura (Gmelin, 1788), in an urban park in southeastern Brazil | journal=Brazilian Journal of Biology | publisher=FapUNIFESP (SciELO) | volume=68 | issue=2 | year=2008 | doi=10.1590/s1519-69842008000200027 | pages=419–426| pmid=18660974 | doi-access=free }} [345] => [346] => [[File:Green-crowned_brilliant_%26_Heliconia_stricta.jpg|thumb|''Heliconia'' species are popular nectar sources for many hummingbirds; here, a [[green-crowned brilliant]] (''Heliodoxa jacula'') visits ''[[Heliconia stricta]]'']] [347] => [348] => Although a high-quality source of energy, nectar is deficient in many [[Macronutrient|macro]]- and [[micronutrient]]s;{{cite journal | last1=Brice | first1=Ann T. | last2=Grau | first2=C. Richard | title=Protein Requirements of Costa's Hummingbirds Calypte costae | journal=Physiological Zoology | publisher=University of Chicago Press | volume=64 | issue=2 | year=1991 | url=https://www.journals.uchicago.edu/doi/abs/10.1086/physzool.64.2.30158193 | doi=10.1086/physzool.64.2.30158193 | pages=611–626| s2cid=87673164 }} it tends to be low in [[lipid]]s, and although it may contain trace quantities of [[amino acid]]s, some essential acids are severely or entirely lacking. Though hummingbird protein requirements appear to be quite small, at 1.5% of the diet, nectar is still an inadequate source; most if not all hummingbirds therefore supplement their diet with the consumption of invertebrates.{{Cite journal |last1=Yanega |first1=Gregor M. |last2=Rubega |first2=Margaret A. |year=2004 |title=Feeding mechanisms: Hummingbird jaw bends to aid insect capture |journal=Nature |volume=428 |issue=6983 |page=615 |bibcode=2004Natur.428..615Y |doi=10.1038/428615a |pmid=15071586 |s2cid=4423676|doi-access=free }} Insectivory is not thought to be calorically important; nonetheless, regular consumption of arthropods is considered crucial for birds to thrive. In fact, it has been suggested that the majority of non-caloric nutritional needs of hummingbirds are met by insectivory, but nectars do contain appreciable quantities of certain [[vitamin]]s and [[mineral]]s.{{cite journal | last1=Carroll | first1=Scott P. | last2=Moore | first2=Laurel | title=Hummingbirds take their vitamins | journal=Animal Behaviour | publisher=Elsevier BV | volume=46 | issue=4 | year=1993 | url=https://www.sciencedirect.com/science/article/abs/pii/S0003347283712613 | doi=10.1006/anbe.1993.1261 | pages=817–820| s2cid=54417626 }} (Note that here, "[[insectivory]]" refers to the consumption of any arthropod, not exclusively insects). [349] => [350] => Though not as insectivorous as once believed, and far less so than most of their relatives and ancestors among the [[Strisores]] (e.g., swifts), insectivory is probably of regular importance to most hummingbirds. About 95% of individuals from 140 species in one study showed evidence of arthropod consumption, while another study found arthropod remains in 79% of over 1600 birds from sites across South and Central America.{{cite journal | last1=Chavez-Ramirez | first1=Felipe | last2=Dowd | first2=McAlister | title=Arthropod Feeding by Two Dominican Hummingbird Species | journal=The Wilson Bulletin | publisher=Wilson Ornithological Society | volume=104 | issue=4 | year=1992 | jstor=4163229 | pages=743–747 | url=http://www.jstor.org/stable/4163229 | access-date=2 September 2023}} Some species have even been recorded to be largely or entirely insectivorous for periods of time, particularly when nectar sources are scarce, and possibly, for some species, with seasonal regularity in areas with a [[wet season]]. Observations of seasonal, near-exclusive insectivory have been made for [[Blue-throated mountaingem|blue-throated hummingbirds]],{{cite journal | last1=Kuban | first1=Joseph F. | last2=Neill | first2=Robert L. | title=Feeding Ecology of Hummingbirds in the Highlands of the Chisos Mountains, Texas | journal=The Condor | publisher=Oxford University Press (OUP) | volume=82 | issue=2 | year=1980 | url=https://academic.oup.com/condor/article-abstract/82/2/180/5204713 | doi=10.2307/1367475 | page=180| jstor=1367475 }} as well as [[swallow-tailed hummingbird]]s in an urban park in Brazil. In Arizona, when nearby nectar sources were seemingly absent, a nesting female broad-tailed hummingbird was recorded feeding only on arthropods for two weeks.{{cite journal | last1=Montgomerie | first1=Robert D. | last2=Redsell | first2=Catherine A. | title=A Nesting Hummingbird Feeding Solely on Arthropods | journal=The Condor | publisher=Oxford University Press (OUP) | volume=82 | issue=4 | year=1980 | url=https://sora.unm.edu/sites/default/files/journals/condor/v082n04/p0463-p0464.pdf | doi=10.2307/1367577 | page=463| jstor=1367577 }} Other studies report 70-100% of feeding time devoted to arthropods; these accounts suggest a degree of adaptability, particularly when appropriate nectar sources are unavailable, although nectarivory always predominates when flowers are abundant (e.g., in non-seasonal tropical habitats). In addition, the aforementioned Arizona study only surveyed a small portion of the study area, and mostly did not observe the bird while she was off the nest. Similar concerns have been raised for other reports, leading to skepticism over whether hummingbirds can in fact subsist without nectar for extended periods at all. [351] => [352] => [[File:Chironomus plumosus01.jpg|thumb|Among the commonest invertebrate food items of hummingbirds are flies, particularly [[Chironomidae|nonbiting midges]], members of the family Chironomidae]] [353] => [354] => Hummingbirds exhibit various feeding strategies and some morphological adaptations for insectivory. Typically, they [[Hawking (birds)|hawk]] for small flying insects, but also glean [[spider]]s from their [[Spiderweb|web]]s. Bill shape may play a role, as hummingbirds with longer or more curved bills may be unable to hawk efficiently, and so rely more heavily on gleaning spiders. Regardless of bill shape, spiders are a common [[prey]] item; other very common prey items include [[flies]], especially those of the family [[Chironomidae]], as well as various [[Hymenoptera]]ns (such as [[wasp]]s and [[ant]]s) and [[Hemiptera]]ns. The aforementioned California study found three species to consume invertebrates from 72 families in 15 orders, with flies alone occurring in over 90% of samples; the three species exhibited high dietary overlap, with little evidence for [[niche partitioning]]. This suggests that prey availability is not a limiting resource for hummingbirds. [355] => [356] => Estimates of overall dietary makeup for hummingbirds vary, but insectivory is often cited as comprising 5-15% of feeding time budgets, typically; 2-12% is a figure that is also cited. In one study, 84% of feeding time was allotted to nectar feeding if breeding females are included, and 89% otherwise; 86% of total feeding records were on nectar. It has been estimated, based on time budgets and other data, that the hummingbird diet is generally about 90% nectar and 10% arthropods by mass.{{cite journal | last1=Weathers | first1=Wesley W. | last2=Stiles | first2=F. Gary | title=Energetics and Water Balance in Free-Living Tropical Hummingbirds | journal=The Condor | publisher=Oxford University Press (OUP) | volume=91 | issue=2 | year=1989 | url=https://academic.oup.com/condor/article-abstract/91/2/324/5189260 | doi=10.2307/1368310 | page=324| jstor=1368310 }} As their [[nestlings]] consume only arthropods, and possibly because their own requirements increase, breeding females spend 3-4 times as long as males foraging for arthropods, although 65-70% of their feeding time is still devoted to nectar. Estimates for overall insectivory can be as low as <5%. Such low numbers have been documented for some species; insects comprised 3% of foraging attempts for Peruvian [[shining sunbeam]]s in one study,{{cite journal | last1=Céspedes | first1=Laura N. | last2=Pavan | first2=Lucas I. | last3=Hazlehurst | first3=Jenny A. | last4=Jankowski | first4=Jill E. | title=The behavior and diet of the Shining Sunbeam (''Aglaeactis cupripennis''): A territorial high-elevation hummingbird | journal=The Wilson Journal of Ornithology | publisher=Wilson Ornithological Society | volume=131 | issue=1 | date=9 April 2019 | url=https://meridian.allenpress.com/wjo/article-abstract/131/1/24/430191/The-behavior-and-diet-of-the-Shining-Sunbeam | doi=10.1676/18-79 | page=24| s2cid=91263467 }} while the [[purple-throated carib]] has been reported to spend <1% of time consuming insects in [[Dominica]]. Both species also have more typical numbers recorded elsewhere, however. Overall, for most hummingbirds, insectivory is an essential and regular, albeit minor, component of the diet, while nectar is the primary feeding focus when conditions allow. It has been shown that floral abundance (but not floral diversity) influences hummingbird diversity, but that arthropod abundance does not (i.e., that it is non-limiting). [357] => [358] => Hummingbirds do not spend all day flying, as the energy cost would be prohibitive; the majority of their activity consists simply of sitting or perching. Hummingbirds eat many small meals and consume around half their weight in nectar (twice their weight in nectar, if the nectar is 25% sugar) each day.{{Cite book |last=Unwin |first=Mike |url=https://books.google.com/books?id=Szh7ENErBUAC&q=hummingbird+twelve+times+their+own+body+weight+in+nectar&pg=PA57 |title=The Atlas of Birds: Diversity, Behavior, and Conservation |publisher=Princeton University Press |year=2011 |isbn=978-1-4008-3825-7 |page=57}} Hummingbirds digest their food rapidly due to their small size and high metabolism; a mean retention time less than an hour has been reported.{{Cite book |last1=Stevens |first1=C. Edward |url=https://books.google.com/books?id=DZuAsci2apAC&q=hummingbird+transit+time+1+hour&pg=PA126 |title=Comparative Physiology of the Vertebrate Digestive System |last2=Hume |first2=Ian D. |publisher=Cambridge University Press |year=2004 |isbn=978-0-521-61714-7 |page=126}} Hummingbirds spend an average of 20% of their time feeding and 75–80% sitting and digesting.{{cite journal |last1=Diamond |first1=Jared M. |last2=Karasov |first2=William H. |last3=Phan |first3=Duong |last4=Carpenter |first4=F. Lynn |title=Digestive physiology is a determinant of foraging bout frequency in hummingbirds |journal=Nature |volume=320 |issue=6057 |pages=62–3 |date=1986 |pmid=3951548 |doi=10.1038/320062a0 |bibcode=1986Natur.320...62D |s2cid=4363635 |url=https://www.nature.com/articles/320062a0}} [359] => [360] => Because their high metabolism makes them vulnerable to [[starvation]], hummingbirds are highly attuned to food sources. Some species, including many found in North America, are territorial and try to guard food sources (such as a feeder) against other hummingbirds, attempting to ensure a future food supply. Additionally, hummingbirds have an enlarged [[hippocampus]], a brain region facilitating spatial memory used to map flowers previously visited during nectar foraging.{{Cite journal |last1=Ward |first1=B.J. |last2=Day |first2=L.B. |last3=Wilkening |first3=S.R. |last4=Wylie |first4=D.R. |last5=Saucier |first5=D.M. |last6=Iwaniuk |first6=A.N. |display-authors=3 |year=2012 |title=Hummingbirds have a greatly enlarged hippocampal formation |journal=Biology Letters |volume=8 |issue=4 |pages=657–659 |doi=10.1098/rsbl.2011.1180 |pmc=3391440 |pmid=22357941}} [361] => [362] => ===Beak specializations=== [363] => {{multiple image [364] => |image1=Eutoxeres aquila 28748616.jpg [365] => |width1=175 [366] => |caption1=Curved beak (approx. 90^o) of the [[white-tipped sicklebill]] [367] => |image2=Centropogon grandidentatus (9349553006).jpg [368] => |width2=150 [369] => |caption2=[[Centropogon]] flowers [370] => |footer=Coevolution of the sicklebill beak curve facilitates both nectar feeding and pollination of long tubular Centropogon flowers. [371] => }} [372] => [373] => The shapes of hummingbird [[beak]]s (also called bills) vary widely as an adaptation for specialized feeding, with some 7000 flowering plants pollinated by hummingbird nectar feeding.{{cite journal |last1=Leimberger|first1=K.G.|last2= Dalsgaard|first2=B.|last3=Tobias|first3=J.A.|last4= Wolf|first4=C.|last5= Betts|first5=M.G. |title=The evolution, ecology, and conservation of hummingbirds and their interactions with flowering plants |journal=Biological Reviews of the Cambridge Philosophical Society |volume=97 |issue=3 |pages=923–959 |date=June 2022 |pmid=35029017 |doi=10.1111/brv.12828|hdl=10044/1/94632 |s2cid=245971244 |hdl-access=free}} Hummingbird beak lengths range from about {{convert|6|mm|in}} to as long as {{convert|110|mm|in}}.{{cite journal |last1=Rico-Guevara |first1=A.|last2= Rubega|first2=M.A.|last3=Hurme|first3=K.J.|last4=Dudley|first4=R. |title=Shifting paradigms in the mechanics of nectar extraction and hummingbird bill morphology |journal=Integrative Organismal Biology|volume=1 |issue=1 |pages=oby006 |date=2019 |pmid=33791513 |pmc=7671138 |doi=10.1093/iob/oby006}} When catching insects in flight, a hummingbird's jaw [[bending|flexes]] downward to widen the beak for successful capture. [374] => [375] => The extreme curved beaks of sicklebills are adapted for extracting nectar from the curved corolla tubes of ''Centropogon'' flowers.{{cite journal |last1=Boehm|first1=M.M.A.|last2=Guevara-Apaza |first2=D.|last3= Jankowski|first3=J.E.|last4=Cronk|first4=Q.C.B.|title=Floral phenology of an Andean bellflower and pollination by buff-tailed sicklebill hummingbird |journal=Ecology and Evolution |volume=12 |issue=6 |pages=e8988 |date=July 2022 |pmid=35784085 |pmc=9168340 |doi=10.1002/ece3.8988|bibcode=2022EcoEv..12E8988B }} Some species, such as hermits (''Phaethornis'' spp.), have long beaks that enable insertion deeply into flowers with long corolla tubes.{{cite journal |last1=Betts|first1=M.G.|last2= Hadley|first2=A.S.|last3= Kress|first3=W.J. |title=Pollinator recognition by a keystone tropical plant |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=112 |issue=11 |pages=3433–8 |date=March 2015 |pmid=25733902 |pmc=4371984 |doi=10.1073/pnas.1419522112 |bibcode=2015PNAS..112.3433B |doi-access=free }} [[Chalcostigma|Thornbills]] have short, sharp beaks adapted for feeding from flowers with short corolla tubes and piercing the bases of longer ones. The beak of the [[fiery-tailed awlbill]] has an upturned tip adapted for feeding on nectar from tubular flowers while hovering.{{cite web |title=Fiery-tailed awlbills |url=https://beautyofbirds.com/fierytailedawlbillhummingbirds/ |publisher=Beauty of Birds |access-date=8 March 2023 |date=16 September 2021}} [376] => [377] => === Perception of sweet nectar === [378] => [379] => Perception of sweetness in nectar evolved in hummingbirds during their [[genetic divergence]] from insectivorous swifts, their closest bird relatives.{{Cite journal |last1=Baldwin |first1=Maude W. |last2=Toda |first2=Yasuka |last3=Nakagita |first3=Tomoya |last4=O'Connell |first4=Mary J. |last5=Klasing |first5=Kirk C. |last6=Misaka |first6=Takumi |last7=Edwards |first7=Scott V. |last8=Liberles |first8=Stephen D. |year=2014 |title=Sensory biology. Evolution of sweet taste perception in hummingbirds by transformation of the ancestral umami receptor |journal=Science |volume=345 |issue=6199 |pages=929–933 |bibcode=2014Sci...345..929B |doi=10.1126/science.1255097 |pmc=4302410 |pmid=25146290}} Although the only known sweet sensory receptor, called [[TAS1R2|T1R2]],{{Cite journal |last=Li|first=X. |year=2009 |title=T1R receptors mediate mammalian sweet and umami taste |journal=American Journal of Clinical Nutrition |volume=90 |issue=3 |pages=733S–37S |doi=10.3945/ajcn.2009.27462G |pmid=19656838 |doi-access=free}} is absent in birds, receptor expression studies showed that hummingbirds adapted a carbohydrate receptor from the [[TAS1R1|T1R1]]-[[TAS1R3|T1R3]] receptor, identical to the one perceived as [[umami]] in humans, essentially repurposing it to function as a nectar sweetness receptor. This adaptation for taste enabled hummingbirds to detect and exploit sweet nectar as an energy source, facilitating their distribution across geographical regions where nectar-bearing flowers are available. [380] => [381] => === Tongue as a micropump === [382] => [[File:PSM V05 D295 Hummingbird tongue.jpg|thumb|Drawing of a hummingbird tongue; 1874, unknown artist. Upon reaching nectar in a flower, the tongue splits into opposing tips fringed with [[Lamella (cell biology)|lamellae]] and grooves, which fill with nectar, then retracts to a cylindrical configuration into the bill to complete the drink.]] [383] => [384] => Hummingbirds drink with their long tongues by rapidly lapping nectar. Their tongues have [[Semicircle|semicircular]] tubes which run down their lengths to facilitate nectar consumption via rapid pumping in and out of the nectar.{{Cite journal |last1=Rico-Guevara |first1=Alejandro |last2=Fan |first2=Tai-Hsi |last3=Rubega |first3=Margaret A. |date=2015-08-22 |title=Hummingbird tongues are elastic micropumps |journal=Proceedings of the Royal Society B |volume=282 |issue=1813 |pages=20151014 |doi=10.1098/rspb.2015.1014 |issn=0962-8452 |pmc=4632618 |pmid=26290074}}{{Cite news |last1=Frank |first1=David |last2=Gorman |first2=James |date=2015-09-08 |title=ScienceTake {{!}} The hummingbird's tongue |work=The New York Times |url=https://www.nytimes.com/video/science/100000003892113/the-hummingbirds-tongue.html |access-date=2015-09-10 |issn=0362-4331}} While capillary action was believed to be what drew nectar into these tubes, high-speed photography revealed that the tubes open down their sides as the tongue goes into the nectar, and then close around the nectar, trapping it so it can be pulled back into the beak over a period of 14 [[millisecond]]s per lick at a rate of up to 20 licks per second.{{Cite journal |last1=Rico-Guevara |first1=A. |last2=Rubega |first2=M.A. |year=2011 |title=The hummingbird tongue is a fluid trap, not a capillary tube |journal=Proceedings of the National Academy of Sciences |volume=108 |issue=23 |pages=9356–360 |bibcode=2011PNAS..108.9356R |doi=10.1073/pnas.1016944108 |pmc=3111265 |pmid=21536916 |doi-access=free}}{{Cite web |last=Mosher|first=D. |date=2 May 2011 |title=High-speed video shows how hummingbirds really drink |url=https://www.wired.com/wiredscience/2011/05/hummingbird-tongue-drinking |access-date=13 August 2022 |publisher=Wired}} The tongue, which is forked, is compressed until it reaches nectar, then the tongue springs open, the rapid action traps the nectar which moves up the grooves, like a [[pump]] action, with [[capillary action]] not involved.{{Cite news |last=Gorman |first=James |date=2015-09-08 |title=The hummingbird's tongue: How it works |work=The New York Times |url=https://www.nytimes.com/2015/09/08/science/the-hummingbirds-tongue-how-it-works.html |access-date=2015-09-10 |issn=0362-4331}} Consequently, tongue flexibility enables accessing, transporting and unloading nectar via pump action, not by a capillary [[syphon]] as once believed.{{Cite journal |last1=Kim |first1=W. |last2=Peaudecerf |first2=F. |last3=Baldwin |first3=M.W. |last4=Bush |first4=J.W. |year=2012 |title=The hummingbird's tongue: A self-assembling capillary syphon |journal=Proceedings of the Royal Society B: Biological Sciences |volume=279 |issue=1749 |pages=4990–996 |doi=10.1098/rspb.2012.1837 |pmc=3497234 |pmid=23075839}} [385] => [386] => [[File:Ruby-Throated Hummingbird.png|thumb|upright|Male [[ruby-throated hummingbird]] (''Archilochus colubris'') with tongue extended]] [387] => [388] => === Feeders and artificial nectar === [389] => [[File:Hummingbirds at feeder.jpg|thumb|Hummingbirds hovering at an artificial nectar feeder]] [390] => [391] => In the wild, hummingbirds visit flowers for food, extracting nectar, which is 55% sucrose, 24% glucose, and 21% fructose on a dry-matter basis.{{Cite journal |last1=Stahl |first1=J.M. |last2=Nepi |first2=M. |last3=Galetto |first3=L. |last4=Guimarães |first4=E. |last5=Machado |first5=S.R. |year=2012 |title=Functional aspects of floral nectar secretion of Ananas ananassoides, an ornithophilous bromeliad from the Brazilian savanna |journal=Annals of Botany |volume=109 |issue=7 |pages=1243–252 |doi=10.1093/aob/mcs053 |pmc=3359915 |pmid=22455992}} Hummingbirds also take sugar-water from [[bird feeder]]s, which allow people to observe and enjoy hummingbirds up close while providing the birds with a reliable source of energy, especially when flower blossoms are less abundant. A negative aspect of artificial feeders, however, is that the birds may seek less flower nectar for food, and so may reduce the amount of pollination their feeding naturally provides.{{Cite journal |last1=Avalos |first1=G. |last2=Soto |first2=A. |last3=Alfaro |first3=W. |year=2012 |title=Effect of artificial feeders on pollen loads of the hummingbirds of Cerro de la Muerte, Costa Rica |journal=Revista de Biología Tropical |volume=60 |issue=1 |pages=65–73 |doi=10.15517/rbt.v60i1.2362 |pmid=22458209 |doi-access=free}} [392] => [393] => White granulated sugar is used in hummingbird feeders in a 20% concentration as a common recipe,{{Cite web |title=Hummingbird Nectar Recipe |date=22 February 2017 |url=https://nationalzoo.si.edu/migratory-birds/hummingbird-nectar-recipe|access-date=2022-09-07 |publisher=Nationalzoo.si.edu}} although hummingbirds will defend feeders more aggressively when sugar content is at 35%, indicating preference for nectar with higher sugar content.{{Cite journal |last1=Rousseu |first1=F. |last2=Charette |first2=Y. |last3=Bélisle |first3=M. |year=2014 |title=Resource defense and monopolization in a marked population of ruby-throated hummingbirds (Archilochus colubris) |journal=Ecology and Evolution |volume=4 |issue=6 |pages=776–793 |doi=10.1002/ece3.972 |pmc=3967903 |pmid=24683460|bibcode=2014EcoEv...4..776R }} Organic and "raw" sugars contain [[iron]], which can be harmful,{{Cite web |date=14 April 2016 |title=How to Make Hummingbird Nectar |url=http://www.audubon.org/news/how-make-hummingbird-nectar |website=Audubon.com |publisher=Audubon Society |language=en}} and brown sugar, [[agave syrup]], [[molasses]], and [[Sugar substitute|artificial sweeteners]] also should not be used.{{Cite web |title=Feeding Hummingbirds |url=http://www.kern.audubon.org/hummer_feeding.htm |website=www.kern.audubon.org |publisher=Audubon California Kern River Preserve |access-date=6 April 2017 |archive-date=8 April 2022 |archive-url=https://web.archive.org/web/20220408140247/http://www.kern.audubon.org/hummer_feeding.htm |url-status=dead }} [[Honey]] is made by bees from the nectar of flowers, but it is not good to use in feeders because when it is diluted with water, [[microorganism]]s easily grow in it, causing it to spoil rapidly.{{Cite web |date=2008-01-09 |title=Feeders and Feeding Hummingbirds |url=http://faq.gardenweb.com/faq/lists/hummingbird/2003021845028716.html |access-date=2009-01-25 |publisher=Faq.gardenweb.com}}{{Cite web |date=2008-11-25 |title=Hummingbird F.A.Q.s from the Southeastern Arizona Bird Observatory |url=http://www.sabo.org/hbfaqs.htm#honey |url-status=dead |archive-url=https://web.archive.org/web/20141102002928/http://sabo.org/hbfaqs.htm#honey |archive-date=2014-11-02 |access-date=2009-01-25 |publisher=Sabo.org}}[http://mdc.mo.gov/discover-nature/outdoor-recreation/nature-viewing/birding/ruby-throated-hummingbirds Attracting Hummingbirds |Missouri Department of Conservation] {{Webarchive|url=https://web.archive.org/web/20120419094054/http://mdc.mo.gov/discover-nature/outdoor-recreation/nature-viewing/birding/ruby-throated-hummingbirds |date=19 April 2012 }} Retrieved on 2013-04-01 [394] => [395] => [[Allura Red AC|Red food dye]] was once thought to be a favorable ingredient for the nectar in home feeders, but it is unnecessary.{{Cite web |last=Chambers |first=Lanny |date=2016 |title=Please Don't Use Red Dye |url=http://www.hummingbirds.net/dye.html |access-date=25 June 2016 |publisher=Hummingbirds.net}} Commercial products sold as "instant nectar" or "hummingbird food" may also contain [[preservative]]s or artificial flavors, as well as dyes, which are unnecessary and potentially harmful.{{Cite web |title=Should I Add Red Dye to My Hummingbird Food? |url=http://www.trochilids.com/dye.html |access-date= 20 March 2010 |publisher=Trochilids.com}} Although some commercial products contain small amounts of nutritional additives, hummingbirds obtain all necessary nutrients from the insects they eat, rendering added nutrients unnecessary.{{cite book |last=Williamson |first=S. L. |title=A Field Guide to Hummingbirds of North America |series=Peterson Field Guide Series |publisher=Houghton Mifflin |location=Boston |year=2002 |isbn=0-618-02496-4}} [396] => [397] => ===Visual cues of foraging=== [398] => [399] => Hummingbirds have exceptional visual acuity providing them with discrimination of food sources while foraging. Although hummingbirds are thought to be attracted to color while seeking food, such as red flowers or artificial feeders, experiments indicate that location and flower nectar quality are the most important "[[beacon]]s" for foraging.{{Cite web |date=28 May 2013 |title=Hummingbirds See Red |url=http://www.audubon.org/news/hummingbirds-see-red |access-date=23 April 2017 |publisher=US National Audubon Society}}{{Cite web |date=16 March 2012 |title=Hummingbirds take no notice of flower color |url=https://phys.org/news/2012-03-hummingbirds.html |access-date=22 April 2017 |publisher=Phys.org}} Hummingbirds depend little on visual cues of flower color to beacon to nectar-rich locations, but rather they use surrounding landmarks to find the nectar reward.{{Cite journal |last1=Hurly |first1=T.A. |last2=Franz |first2=S |last3=Healy |first3=S.D. |year=2010 |title=Do rufous hummingbirds (''Selasphorus rufus'') use visual beacons? |journal=Animal Cognition |volume=13 |issue=2 |pages=377–383 |doi=10.1007/s10071-009-0280-6 |pmid=19768647 |s2cid=9189780}}{{Cite journal |last1=Hurly |first1=T.A. |last2=Fox |first2=T.A.O. |last3=Zwueste |first3=D.M. |last4=Healy |first4=S.D. |year=2014 |title=Wild hummingbirds rely on landmarks not geometry when learning an array of flowers |url=https://research-repository.st-andrews.ac.uk/bitstream/10023/6422/1/Hurly_et_al_Anim_Cog_14.pdf |journal=Animal Cognition |volume=17 |issue=5 |pages=1157–165 |doi=10.1007/s10071-014-0748-x |pmid=24691650 |hdl-access=free |hdl=10023/6422 |s2cid=15169177}}{{cite journal |last1=Hornsby |first1=Mark A.W. |last2=Healy |first2=Susan D. |last3=Hurly |first3=T. Andrew |title=Wild hummingbirds can use the geometry of a flower array |journal=Behavioural Processes |volume=139 |year=2017|pmid=28161360|issn=0376-6357 |doi=10.1016/j.beproc.2017.01.019 |pages=33–37|hdl=10023/12652 |s2cid=10692583 |hdl-access=free }} [400] => [401] => In at least one hummingbird species – the [[green-backed firecrown]] (''Sephanoides sephaniodes'') – flower colors preferred are in the red-green wavelength for the bird's visual system, providing a higher [[contrast (vision)|contrast]] than for other flower colors.{{Cite journal |last1=Herrera |first1=G |last2=Zagal |first2=J. C. |last3=Diaz |first3=M |last4=Fernández |first4=M. J. |last5=Vielma |first5=A |last6=Cure |first6=M |last7=Martinez |first7=J |last8=Bozinovic |first8=F |last9=Palacios |first9=A. G. |year=2008 |title=Spectral sensitivities of photoreceptors and their role in colour discrimination in the green-backed firecrown hummingbird (''Sephanoides sephaniodes'') |journal=Journal of Comparative Physiology A |volume=194 |issue=9 |pages=785–794 |doi=10.1007/s00359-008-0349-8 |pmid=18584181 |hdl-access=free |hdl=10533/142104 |s2cid=7491787}} Further, the crown plumage of firecrown males is highly iridescent in the red wavelength range (peak at 650 nanometers), possibly providing a competitive advantage of [[dominance (ethology)|dominance]] when foraging among other hummingbird species with less colorful plumage. The ability to discriminate colors of flowers and plumage is enabled by a visual system having four single [[cone cell]]s and a double cone screened by [[photoreceptor cell|photoreceptor]] [[oil droplet]]s which enhance color discrimination. [402] => [403] => ===Olfaction=== [404] => [405] => While hummingbirds rely primarily on vision and hearing to assess competition from bird and insect foragers near food sources, they may also be able to detect by [[olfaction|smell]] the presence in nectar of insect defensive chemicals (such as [[formic acid]]) and aggregation [[pheromone]]s of foraging ants, which discourage feeding.{{Cite journal |last1=Kim |first1=Ashley Y. |last2=Rankin |first2=David T. |last3=Rankin |first3=Erin E. Wilson |year=2021 |title=What is that smell? Hummingbirds avoid foraging on resources with defensive insect compounds |journal=Behavioral Ecology and Sociobiology |volume=75 |issue=9 |page=132 |doi=10.1007/s00265-021-03067-4 |issn=0340-5443 |doi-access=free}} [406] => [407] => == In myth and culture == [408] => [[File:Líneas de Nazca, Nazca, Perú, 2015-07-29, DD 52.JPG|thumb|Nazca Lines - hummingbird]][[File:Caribbean Airlines Boeing 737-800 LDS.jpg|thumb|Hummingbird emblem on [[Caribbean Airlines]]]] [409] => [410] => [[Aztecs]] wore hummingbird [[amulet|talismans]], artistic representations of hummingbirds and [[fetishism|fetishes]] made from actual hummingbird parts as emblematic for vigor, energy, and propensity to do work along with their sharp beaks that symbolically mimic instruments of weaponry, bloodletting, penetration, and intimacy. Hummingbird talismans were prized as drawing sexual potency, energy, vigor, and skill at arms and [[warfare]] to the wearer.{{Cite book |last1=Werness|first1=Hope B. |url=https://books.google.com/books?id=fr2rANLrPmoC&pg=PA228 |title=The Continuum Encyclopedia of Animal Symbolism in Art |last2=Benedict|first2=Joanne H.|last3=Thomas|first3=Scott |last4=Ramsay-Lozano|first4=Tiffany |publisher=[[Continuum International Publishing Group]] |year=2004 |isbn=978-0-8264-1525-7 |page=229}} The Aztec god of war [[Huitzilopochtli]] is often depicted in art as a hummingbird.{{cite web|title=Huitzilopochtli|url=https://www.britannica.com/topic/Huitzilopochtli|publisher=Encyclopaedia Britannica|access-date=5 March 2023|date=2023}} Aztecs believed that fallen warriors would be [[reincarnation|reincarnated]] as hummingbirds.{{Cite book |last=MacDonald|first=Fiona |url=https://books.google.com/books?id=a2VgkHouDLkC&q=hummingbird+butterfly+warriors+Aztec&pg=PA25-IA3 |title=How to Be an Aztec Warrior |date=2008 |publisher=National Geographic Books |isbn=978-1-4263-0168-1 |page=25}} The [[Nahuatl]] word ''huitzil'' translates to ''hummingbird''. One of the [[Nazca Lines]] depicts a hummingbird (right).{{cite magazine |last1=Golomb|first1=Jason |title=Nasca lines |url=https://www.nationalgeographic.com/history/archaeology/nasca-lines/ |magazine=National Geographic |access-date=5 March 2023 |date=28 September 2019|archive-url=https://web.archive.org/web/20190928050205/https://www.nationalgeographic.com/history/archaeology/nasca-lines/ |archive-date=28 September 2019 }} [411] => [412] => [[Trinidad and Tobago]], known as "The land of the hummingbird," displays a hummingbird on its [[coat of arms of Trinidad and Tobago|coat of arms]],{{Cite web |date=2016 |title=National Symbols of Trinidad and Tobago |url=http://www.nalis.gov.tt/Research/SubjectGuide/NationalSymbols/tabid/215/Default.aspx?PageContentMode=1 |url-status=dead |archive-url=https://web.archive.org/web/20160507114705/http://www.nalis.gov.tt/Research/SubjectGuide/NationalSymbols/tabid/215/Default.aspx?PageContentMode=1 |archive-date=7 May 2016 |access-date=18 April 2016 |publisher=National Library of Trinidad and Tobago, Port of Spain}} 1-cent coin,{{Cite web |date=2015 |title=Coins of Trinidad and Tobago |url=http://www.central-bank.org.tt/content/coins |url-status=dead |archive-url=https://web.archive.org/web/20170207120816/http://www.central-bank.org.tt/content/coins |archive-date=7 February 2017 |access-date=18 April 2016 |publisher=Central Bank of Trinidad and Tobago, Port of Spain}} and [[livery]] on its national airline, [[Caribbean Airlines]].{{cite web |title=Brand Refresh: Introducing the new Caribbean Airlines |url=https://www.caribbean-airlines.com/#/pages/brand-refresh |publisher=Caribbean Airlines |access-date=5 March 2023 |date=1 March 2020}} [413] => [414] => [[Mt. Umunhum]] in the [[Santa Cruz Mountains]] of [[Northern California]] is [[Ohlone languages|Ohlone]] for "resting place of the hummingbird".{{Cite web |title=Sierra Azul Preserve - Overview |url=http://www.openspace.org/preserves/sierra-azul#tabs-preserve_tabs-middle-4|date=2021 |access-date=5 March 2023 |publisher=[[Midpeninsula Regional Open Space District]]}} [415] => [416] => The [[Gibson Hummingbird]] is an [[acoustic guitar]] model that incorporates a pickguard in the shape of a hummingbird by Gibson Brands, a major guitar manufacturer.{{cite web |title=Hummingbird Original |url=https://www.gibson.com/en-US/Acoustic-Guitar/ACCFR6729/Antique-Natural |publisher=Gibson Brands, Inc. |access-date=5 March 2023 |date=2023}} [417] => [418] => During the costume competition of the [[Miss Universe 2016]] beauty pageant, [[Miss Ecuador]], Connie Jiménez, wore a costume inspired by hummingbird wing feathers.{{Cite news |last=Garcia |first=Alexander |date=26 January 2017 |title=Connie Jiménez dressed as a hummingbird in the Miss Universe preliminary competition (translated from Spanish) |work=El Commercio |url=https://www.elcomercio.com/tendencias/entretenimiento/conniejimenez-missecuador-missuniverso-trajes-competenciapreliminar.html |access-date=5 March 2023}} [419] => [420] => == Gallery == [421] => [422] => [423] => File:Haeckel Trochilidae.jpg|A color plate illustration from [[Ernst Haeckel]]'s ''[[Kunstformen der Natur]]'' (1899), showing a variety of hummingbirds [424] => File:AnnasHummingbird-NestCollage.png|Fallen Anna's hummingbird nest shown next to a [[toothpick]] for scale [425] => [426] => [427] => == See also == [428] => {{Portal|Birds}} [429] => * [[AeroVironment Nano Hummingbird]] – artificial hummingbird [430] => [431] => == Notes == [432] => {{notelist}} [433] => [434] => == References == [435] => {{Reflist}} [436] => [437] => == External links == [438] => [439] => {{Commons|Trochilidae}} [440] => {{Wikispecies|Trochilidae}} [441] => {{Wikiquote|Hummingbirds}} [442] => [443] => * [http://hummingbirdwebsite.com The Hummingbird Website] Hummingbird photos, videos, articles, links, frequently asked questions [444] => * [http://www.birdphotos.com/photos/index.php?q=gallery&g2_itemId=2182 High-resolution photo gallery of almost 100 species] [445] => * [http://www.michaeldanielho.com/mdh-5g.html High-resolution photo gallery of many species of hummingbirds] [446] => * [https://web.archive.org/web/20170301202153/http://www.learner.org/jnorth/tm/humm/tongue_fluid_trap.html Video of hummingbird tongue acting as a micropump during nectar feeding] [447] => [448] => {{Taxonbar|from=Q43624}} [449] => {{Authority control}} [450] => [451] => [[Category:Hummingbirds|Hummingbirds]] [452] => [[Category:Birds of the Americas|*]] [453] => [[Category:Trochiliformes|*]] [454] => [[Category:Articles containing video clips]] [455] => [[Category:National symbols of Trinidad and Tobago]] [456] => [[Category:Taxa named by Nicholas Aylward Vigors]] [457] => [[Category:Extant Rupelian first appearances]] [] => )

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Hummingbird

The Wikipedia page for "Hummingbird" provides a comprehensive overview of this small bird species. Hummingbirds are known for their unique ability to hover in mid-air and fly backwards, as well as their iridescent feathers and ability to rapidly beat their wings.

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About

Hummingbirds are known for their unique ability to hover in mid-air and fly backwards, as well as their iridescent feathers and ability to rapidly beat their wings. This page goes into detail about the physical characteristics, behavior, habitat, and distribution of hummingbirds, providing information about various species within the family. It also discusses the biological adaptations that allow hummingbirds to feed on nectar, their primary source of nutrition. Additionally, the page explores the importance of hummingbirds as pollinators and their role in plant reproduction. The article concludes by mentioning the conservation challenges facing hummingbirds due to habitat loss, climate change, and other threats, as well as various conservation efforts aimed at protecting these fascinating and essential creatures. Overall, this Wikipedia page serves as a valuable resource for anyone interested in learning about hummingbirds.

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