This is a list of bird species by global population, divided by

bird classification This article lists living Order (biology), orders and Family (biology), families of birds. The links below should then lead to family accounts and hence to individual species. The passerine, passerines (perching birds) alone account for well o ...

. While numbers are estimates, they have been made by the experts in their fields. For more information on how these estimates were ascertained, see Wikipedia's articles on

population biology The term population biology has been used with different meanings. In 1971 Edward O. Wilson ''et al''. used the term in the sense of applying mathematical models to population genetics, community ecology, and population dynamics. Alan Hastings us ...

and

population ecology Population ecology is a sub-field of ecology that deals with the dynamics of species populations and how these populations interact with the environment, such as birth and death rates, and by immigration and emigration. The discipline is importa ...

. Contributing organizations include the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding ...

, and

Partners in Flight Partners in Flight / Compañeros en Vuelo / Partenaires d’Envol is an organization launched in 1990 in response to growing concerns about declines in the populations of many land bird species, and to emphasize the conservation of birds not covered ...

. The average global population of all mature birds is estimated to be somewhat less than 90 billion (actually, somewhere between 40 and 130 billion; this too is a rough estimate). The total population including younglings is somewhat higher during the breeding season of each species. This list is incomplete, because experts have not estimated all bird numbers. For example, the

spectacled flowerpecker The spectacled flowerpecker (''Dicaeum dayakorum'') is a species of bird belonging to the flowerpecker family, Dicaeidae. It was first observed in 2009 in the forests of Borneo, but due to limited information and the lack of a specimen for scient ...

was only discovered in 2010, and did not receive its scientific name (''Dicaeum dayakorum'') until 2019,Saucier, Jacob R.; Milensky, Christopher M.; Caraballo-Ortiz, Marcos A.; Ragai, Roslina; Dahlan, N. Faridah; Edwards, David P. (2019-10-17). "A distinctive new species of flowerpecker (Passeriformes: Dicaeidae) from Borneo". Zootaxa. 4686 (4): 451–464. doi:10.11646/zootaxa.4686.4.1. ISSN 1175-5334. adding to the other 73 new bird species described by

ornithologist Ornithology is a branch of zoology that concerns the "methodological study and consequent knowledge of birds with all that relates to them." Several aspects of ornithology differ from related disciplines, due partly to the high visibility and th ...

s from 2000 – 2009.Reuters.
''"Spectacled flowerpecker" bird found in Borneo''
scientificamerican.com, 13 January 2010, accessed on 15 January 2010.Walton, Doreen, science reporter.
''New bird species found in rainforests of Borneo''
BBC News, news.bbc.co.uk, 14 January 2010, accessed on 15 January 2010. Global population estimates for many of these at this time would lack accuracy. All numbers are estimates, because they are taken by

observation Observation is the active acquisition of information from a primary source. In living beings, observation employs the senses. In science, observation can also involve the perception and recording of data via the use of scientific instruments. The ...

, and a given number of 50

slender-billed curlew The slender-billed curlew (''Numenius tenuirostris'') is a bird in the wader family Scolopacidae. Isotope analysis suggests the majority of the former population bred in the Kazakh Steppe despite a record from the Siberian swamps, and was migr ...

s does not necessarily mean there are 10 more of this species than the

black stilt The black stilt (''Himantopus novaezelandiae'') or kakī (Māori) is a wading bird found in New Zealand. It is one of the world's rarest birds, with 169 adults surviving in the wild as of May 2020. Adult kakī have distinctive black plumage, lo ...

, which has been estimated at 40: there is a possibility that the latter species has a larger population than the former. This list should not be taken that literally. An estimate of 250 shore dotterels compared with 4,500 – 5,000

wrybill The wrybill or (in Māori) ngutuparore (''Anarhynchus frontalis'') is a species of plover endemic to New Zealand. It is the only species of bird in the world with a beak that is bent sideways in one direction, always to the right (in the crossbil ...

s, on the other hand, means that the latter has well over one

order of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...

more individuals than the former. The wrybill only has approximately one tenth the population of

great skua The great skua (''Stercorarius skua''), sometimes known by the name bonxie in Britain, is a large seabird in the skua family Stercorariidae. It is roughly the size of a herring gull. It mainly eats fish caught at the sea surface or taken fr ...

s (48,000), which are outnumbered ~10:1 by the

pigeon guillemot The pigeon guillemot (''Cepphus columba'') () is a species of bird in the auk family, Alcidae. One of three species in the genus ''Cepphus'', it is most closely related to the spectacled guillemot. There are five subspecies of the pigeon guille ...

(470,000). It is these large differences between species that this list tries to convey.

By taxonomy

Notes

:1.Amount of quantified species contained in the list as of the "Retrieved" date in the corresponding citation. The amount of species in each order is according to the IUCN and BirdLife International; bird taxonomy is currently in flux and these figures may soon change. :2.Preliminary estimate. :3.Mature only.

References

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Birds Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

By taxonomy

See also

Notes

References