How we know
The Bird Atlas is built to be trustworthy. Every number has a source and a date, every ecological claim carries an evidence grade, and every image and recording is credited under an open licence.
(01) Method
Principles
- Nothing invented. Facts, measurements, dates and population figures come from the sources listed on each profile. Where reliable information does not exist, the atlas says “not documented” instead of estimating.
- Status with a date. Conservation categories follow the IUCN Red List as assessed by BirdLife International, shown with the year of assessment. Some national listings differ and are noted.
- Estimates are labelled. Population figures carry their year and source; charts show only documented counts and published estimates, never interpolated values.
- Evidence is graded. Ecological relationships and the consequences of losing a species are marked documented, likely or hypothesised. Evolutionary claims are marked established, well supported or debated.
- Taxonomy varies. Authorities sometimes disagree on species limits. Profiles follow BirdLife International and explain differences where they matter.
(02) Evidence grades
Reading the labels
(03) Authorities
Where the data comes from
285+ individual references across 41 species profiles, 10 food webs and 6 ecological roles.
- IUCN Red List of Threatened Species — Conservation categories and criteria.
- BirdLife International — Data Zone — Red List assessments for birds, assessment years, population estimates and trends, country lists.
- Cornell Lab of Ornithology — All About Birds / Birds of the World — Measurements, behaviour and longevity records for many species.
- British Trust for Ornithology — BirdFacts — Measurements and longevity records for European species.
- New Zealand Birds Online & NZ Department of Conservation — New Zealand species, including kākāpō counts and extinct taxa.
- U.S. Fish & Wildlife Service — Recovery data for the bald eagle, California condor and whooping crane.
- Peer-reviewed literature — Ecological relationships, case studies and extinction research — cited by DOI on each page.
- iNaturalist — Community-verified photographs and sound recordings under open licences.
- Natural Earth — Public-domain country boundaries for all maps.
(04) Media credits
Images & recordings
159 items · Unknown (41) · CC BY 4.0 (61) · CC0 1.0 (34) · CC BY-SA 4.0 (11) · Public Domain (7) · CC BY-SA 3.0 DE (4) · CC BY-SA 3.0 (1)
Photographs and recordings were selected from community-verified (research-grade) iNaturalist observations and museum open-access collections. Only CC0, CC BY, CC BY-SA and public-domain works are used. Images were resized and recompressed; recordings were trimmed and converted to MP3 — as noted in each credit.
| Item | Creator | Licence | Source |
|---|---|---|---|
| Andean Condor — main image | |||
| Andean Condor — gallery 1 | Frank Dietze | CC BY 4.0 | Link ↗ |
| Andean Condor — gallery 2 | Sebastian Serna Muñoz | CC BY 4.0 | Link ↗ |
| Atlantic Puffin — main image | |||
| Atlantic Puffin — gallery 1 | Brian Gratwicke | CC BY 4.0 | Link ↗ |
| Atlantic Puffin — gallery 2 | Diego González Dopico | CC BY 4.0 | Link ↗ |
| Atlantic Puffin — recording | Killian Sullivan | CC0 1.0 | Link ↗ |
| Bald Eagle — main image | |||
| Bald Eagle — gallery 1 | Justin Flint | CC BY 4.0 | Link ↗ |
| Bald Eagle — gallery 2 | Judy Gallagher | CC BY-SA 4.0 | Link ↗ |
| Bald Eagle — recording | Doug Hynes | CC BY-SA 4.0 | Link ↗ |
| California Condor — main image | |||
| California Condor — gallery 1 | Brooke J. | CC BY 4.0 | Link ↗ |
| California Condor — gallery 2 | Rick Mandel | CC BY 4.0 | Link ↗ |
| Carolina Parakeet — main image | |||
| Carolina Parakeet — gallery 1 | Naturalis Biodiversity Center, Leiden (specimen RMNH.AVES.110077) | CC0 1.0 | Link ↗ |
| Carolina Parakeet — gallery 2 | Naturalis Biodiversity Center, Leiden (specimen RMNH.AVES.110115) | CC0 1.0 | Link ↗ |
| Clark's Nutcracker — main image | |||
| Clark's Nutcracker — gallery 1 | Millie Basden | CC BY 4.0 | Link ↗ |
| Clark's Nutcracker — gallery 2 | Millie Basden | CC BY 4.0 | Link ↗ |
| Clark's Nutcracker — recording | Diana Doyle | CC BY-SA 4.0 | Link ↗ |
| Common Kingfisher — main image | |||
| Common Kingfisher — gallery 1 | Alexis Lours | CC BY 4.0 | Link ↗ |
| Common Kingfisher — gallery 2 | Frank Sengpiel | CC BY 4.0 | Link ↗ |
| Common Kingfisher — recording | Yves Bas | CC BY 4.0 | Link ↗ |
| Common Ostrich — main image | |||
| Common Ostrich — gallery 1 | Dave Brown | CC0 1.0 | Link ↗ |
| Common Ostrich — gallery 2 | Jan Ebr & Ivana Ebrová | CC BY 4.0 | Link ↗ |
| Dodo — main image | |||
| Dodo — gallery 1 | Vanessa R. Rhue / Yale Peabody Museum (specimen YPM ORN 103123) | CC0 1.0 | Link ↗ |
| Dodo — gallery 2 | F.W. Frohawk, Plate 24 in Walter Rothschild, Extinct Birds (London, 1907). Scan: Boston Public Library via Internet Archive, 1907 | Public Domain | Link ↗ |
| Emperor Penguin — main image | |||
| Emperor Penguin — gallery 1 | Denis Luyten | Public Domain | Link ↗ |
| Emperor Penguin — gallery 2 | Christopher Michel | CC BY 4.0 | Link ↗ |
| Emperor Penguin — recording | steve | CC BY-SA 4.0 | Link ↗ |
| Eurasian Hoopoe — main image | |||
| Eurasian Hoopoe — gallery 1 | Luiz Lapa | CC BY 4.0 | Link ↗ |
| Eurasian Hoopoe — gallery 2 | Dario Taraborelli | CC0 1.0 | Link ↗ |
| Eurasian Hoopoe — recording | Sonothèque ADVL | CC0 1.0 | Link ↗ |
| Eurasian Jay — main image | |||
| Eurasian Jay — gallery 1 | Rhys | CC BY 4.0 | Link ↗ |
| Eurasian Jay — gallery 2 | Yavuz Korkmaz | CC BY 4.0 | Link ↗ |
| Eurasian Jay — recording | Christian Kahle | CC0 1.0 | Link ↗ |
| Great Auk — main image | |||
| Great Auk — gallery 1 | Brian K. Schmidt / Smithsonian Institution, National Museum of Natural History (specimen USNM 57338) | CC0 1.0 | Link ↗ |
| Great Auk — gallery 2 | © The Trustees of the Natural History Museum, London (specimen NHMUK E/1941.1.1.1) | CC BY 4.0 | Link ↗ |
| Great Hornbill — main image | |||
| Great Hornbill — gallery 1 | Lee Ismail | CC BY 4.0 | Link ↗ |
| Great Hornbill — gallery 2 | Rohit Naniwadekar | CC BY 4.0 | Link ↗ |
| Great Hornbill — recording | Hans Lütgens / Tierstimmenarchiv, Museum für Naturkunde Berlin | CC BY-SA 3.0 DE | Link ↗ |
| Great Tit — main image | |||
| Great Tit — gallery 1 | Nicolás Tamargo | CC0 1.0 | Link ↗ |
| Great Tit — gallery 2 | Ирина Хохрякова | CC BY 4.0 | Link ↗ |
| Great Tit — recording | Sonothèque ADVL | CC0 1.0 | Link ↗ |
| Greater Honeyguide — main image | |||
| Greater Honeyguide — gallery 1 | Jean-Paul Boerekamps | CC0 1.0 | Link ↗ |
| Greater Honeyguide — gallery 2 | i_c_riddell | CC BY 4.0 | Link ↗ |
| Greater Honeyguide — recording | suncana | CC BY 4.0 | Link ↗ |
| Guanay Cormorant — main image | |||
| Guanay Cormorant — gallery 1 | Christoph Moning | CC BY 4.0 | Link ↗ |
| Guanay Cormorant — gallery 2 | Asiel Olivares | CC BY 4.0 | Link ↗ |
| Harpy Eagle — main image | |||
| Harpy Eagle — gallery 1 | Christoph Moning | CC BY 4.0 | Link ↗ |
| Harpy Eagle — gallery 2 | Irene | CC0 1.0 | Link ↗ |
| Harpy Eagle — recording | Hans Lütgens / Tierstimmenarchiv, Museum für Naturkunde Berlin | CC BY-SA 3.0 DE | Link ↗ |
| Huia — main image | |||
| Huia — gallery 1 | Naturalis Biodiversity Center, Leiden (specimen RMNH.AVES.110081) | CC0 1.0 | Link ↗ |
| Huia — gallery 2 | Naturalis Biodiversity Center, Leiden (specimens RMNH.AVES.110101 and RMNH.AVES.110102) | CC0 1.0 | Link ↗ |
| Hyacinth Macaw — main image | |||
| Hyacinth Macaw — gallery 1 | R Vasconcellos | CC BY 4.0 | Link ↗ |
| Hyacinth Macaw — gallery 2 | Chris Kirby-Lambert | CC BY 4.0 | Link ↗ |
| Hyacinth Macaw — recording | Jennifer Rycenga | CC BY 4.0 | Link ↗ |
| Kākāpō — main image | |||
| Laughing Owl — main image | |||
| Laughing Owl — gallery 1 | Naturalis Biodiversity Center, Leiden (specimen RMNH.AVES.110069) | CC0 1.0 | Link ↗ |
| Laughing Owl — gallery 2 | Naturalis Biodiversity Center, Leiden (specimen ZMA.AVES.1492) | CC0 1.0 | Link ↗ |
| Mauritius Kestrel — main image | |||
| Mauritius Kestrel — gallery 1 | Robert Martin | CC BY 4.0 | Link ↗ |
| Northern Bald Ibis — main image | |||
| Northern Bald Ibis — gallery 1 | Diego González Dopico | CC BY 4.0 | Link ↗ |
| Northern Bald Ibis — gallery 2 | Andrea Poggi | CC BY 4.0 | Link ↗ |
| Northern Bald Ibis — recording | Hans Lütgens / Tierstimmenarchiv, Museum für Naturkunde Berlin | CC BY-SA 3.0 DE | Link ↗ |
| Paradise Parrot — main image | |||
| Paradise Parrot — gallery 1 | Natural History Museum, University of Oslo (specimen NHMO-BI-64259/1-P) | CC BY 4.0 | Link ↗ |
| Paradise Parrot — gallery 2 | Boheme Jennifer Rawoteea / Museums Victoria (specimen NMV BE 1414) | CC BY 4.0 | Link ↗ |
| Passenger Pigeon — main image | |||
| Passenger Pigeon — gallery 1 | Donald E. Hurlbert / Smithsonian Institution, National Museum of Natural History (specimen USNM 223979) | CC0 1.0 | Link ↗ |
| Passenger Pigeon — gallery 2 | Naturalis Biodiversity Center, Leiden (specimen RMNH.AVES.110092) | CC0 1.0 | Link ↗ |
| Peregrine Falcon — main image | |||
| Peregrine Falcon — gallery 1 | Shirley Zundell | CC BY 4.0 | Link ↗ |
| Peregrine Falcon — gallery 2 | Nicolás Villaseca Merino | CC BY-SA 4.0 | Link ↗ |
| Peregrine Falcon — recording | Sonothèque ADVL | CC0 1.0 | Link ↗ |
| Philippine Eagle — main image | |||
| Philippine Eagle — gallery 1 | Wouter Beukema | CC BY 4.0 | Link ↗ |
| Philippine Eagle — gallery 2 | Wouter Beukema | CC BY 4.0 | Link ↗ |
| Red-billed Oxpecker — main image | |||
| Red-billed Oxpecker — gallery 1 | scaup | CC BY 4.0 | Link ↗ |
| Red-billed Oxpecker — gallery 2 | Asher P Higgins | CC BY 4.0 | Link ↗ |
| Red-billed Oxpecker — recording | Hans Lütgens / Tierstimmenarchiv, Museum für Naturkunde Berlin | CC BY-SA 3.0 DE | Link ↗ |
| Resplendent Quetzal — main image | |||
| Resplendent Quetzal — gallery 1 | Cephas | CC BY-SA 4.0 | Link ↗ |
| Resplendent Quetzal — gallery 2 | Morten Ross | CC BY 4.0 | Link ↗ |
| Resplendent Quetzal — recording | anasacuta | CC BY 4.0 | Link ↗ |
| Rodrigues Solitaire — main image | |||
| Rodrigues Solitaire — gallery 1 | F.W. Frohawk, Plate 23 in Walter Rothschild, Extinct Birds (London, 1907). Scan: Boston Public Library via Internet Archive, 1907 | Public Domain | Link ↗ |
| Rodrigues Solitaire — gallery 2 | © The Trustees of the Natural History Museum, London (specimen NHMUK PV A 3506) | CC BY 4.0 | Link ↗ |
| Ruby-throated Hummingbird — main image | |||
| Ruby-throated Hummingbird — gallery 1 | David Bird | CC0 1.0 | Link ↗ |
| Ruby-throated Hummingbird — gallery 2 | Chrissy McClarren and Andy Reago | CC0 1.0 | Link ↗ |
| Ruby-throated Hummingbird — recording | Jonathon Jongsma | CC BY-SA 3.0 | Link ↗ |
| South Island Giant Moa — main image | |||
| South Island Giant Moa — gallery 1 | Vanessa R. Rhue / Yale Peabody Museum (specimen YPM VP 009206) | CC0 1.0 | Link ↗ |
| Southern Cassowary — main image | |||
| Southern Cassowary — gallery 1 | Oscar Dove | CC BY 4.0 | Link ↗ |
| Southern Cassowary — gallery 2 | Wairambar Rainforest | CC BY 4.0 | Link ↗ |
| Spix’s Macaw — main image | |||
| Spix’s Macaw — gallery 1 | Etna 1984 | CC BY-SA 4.0 | Link ↗ |
| Spix’s Macaw — gallery 2 | Daderot | Public Domain | Link ↗ |
| Spoon-billed Sandpiper — main image | |||
| Spoon-billed Sandpiper — gallery 1 | Sunny Zhang 张迎新 | CC0 1.0 | Link ↗ |
| Spoon-billed Sandpiper — gallery 2 | Sunny Zhang 张迎新 | CC0 1.0 | Link ↗ |
| Toco Toucan — main image | |||
| Toco Toucan — gallery 1 | Miguel A. Paixão | CC BY 4.0 | Link ↗ |
| Toco Toucan — gallery 2 | Francisco V. Bezerra Neto | CC BY-SA 4.0 | Link ↗ |
| Toco Toucan — recording | Pedro Henrique Maloso Ramos | CC BY 4.0 | Link ↗ |
| Wandering Albatross — main image | |||
| Wandering Albatross — gallery 1 | Liam Quinn | CC BY-SA 4.0 | Link ↗ |
| Wandering Albatross — gallery 2 | eloise kerroux | CC BY 4.0 | Link ↗ |
| Western Barn Owl — main image | |||
| Western Barn Owl — gallery 1 | Chris Kirby-Lambert | CC BY 4.0 | Link ↗ |
| Western Barn Owl — gallery 2 | Frank Sengpiel | CC BY 4.0 | Link ↗ |
| Western Barn Owl — recording | Christoph Moning | CC BY 4.0 | Link ↗ |
| White-rumped Vulture — main image | |||
| White-rumped Vulture — gallery 1 | Ashok Sengupta | CC BY 4.0 | Link ↗ |
| White-rumped Vulture — gallery 2 | Tom Heijnen | CC BY 4.0 | Link ↗ |
| Whooping Crane — main image | |||
| Whooping Crane — gallery 1 | Lauren McLaurin | CC BY 4.0 | Link ↗ |
| Whooping Crane — gallery 2 | Cody Delano | CC BY 4.0 | Link ↗ |
| Whooping Crane — recording | JD Flores | CC0 1.0 | Link ↗ |
| Place — Ladário, near Corumbá, Mato Grosso do Sul, Brazil (Pantanal), July 2024 | Thomaz Ricardo Favreto Sinani (iNaturalist) | CC BY 4.0 | Link ↗ |
| Place — Yosemite National Park, California, USA (Sierra Nevada), July 2018 | Nelson Balcar (iNaturalist) | CC BY 4.0 | Link ↗ |
| Place — Islas Ballestas, off Paracas, Ica Region, Peru, October 2025 | Michal Honskus (iNaturalist) | CC BY 4.0 | Link ↗ |
| Place — Velavadar (Blackbuck National Park), Bhavnagar district, Gujarat, India, January 2026 | Кирилл / kirill_petrov (iNaturalist) | CC BY 4.0 | Link ↗ |
| Place — Dartmoor National Park, near Newton Abbot, Devon, England, UK, September 2025 | Kian Hayles-Cotton (iNaturalist) | CC0 1.0 | Link ↗ |
| Place — Cape Tribulation, Daintree, Queensland, Australia (Wet Tropics), March 2021 | Tony Eales (iNaturalist) | CC BY-SA 4.0 | Link ↗ |
| Place — Black River Gorges National Park, Plaines Wilhems District, Mauritius, April 2024 | Emanuele Santarelli (iNaturalist) | CC BY-SA 4.0 | Link ↗ |
| Place — Tarangire National Park, Manyara Region, Tanzania, August 2023 | Henggang Cui (iNaturalist) | CC0 1.0 | Link ↗ |
| Place — Waters off South Georgia, South Atlantic sector of the Southern Ocean, December 2024 | Ryan F. Mandelbaum (iNaturalist) | CC BY 4.0 | Link ↗ |
| Place — Kaitoke, Upper Hutt, Wellington Region, New Zealand, October 2026 | Colin Meurk (iNaturalist) | CC BY 4.0 | Link ↗ |
| Evolution — An 1884 lithograph of the Berlin Archaeopteryx, drawn from the fossil itself, which was found near Eichstätt, Bavaria, in the 1870s. About 150 million years old (Late Jurassic), it combines teeth, clawed fingers and a long bony tail with fully formed flight feathers. | Lithograph of the Berlin specimen, Taf. I in W. Dames, 'Ueber Archaeopteryx', Palaeontologische Abhandlungen 2 (Berlin: G. Reimer, 1884). Scan: Smithsonian Libraries via Biodiversity Heritage Library / Internet Archive, 1884 | Public Domain | Link ↗ |
| Evolution — Hesperornis regalis, a flightless, toothed diving bird from the Late Cretaceous inland sea of North America (Niobrara Formation, Kansas). Its wings were reduced to tiny vestiges; it swam with its feet. | Michael Brett-Surman / Smithsonian Institution, National Museum of Natural History (specimen USNM V 4978) | CC0 1.0 | Link ↗ |
| Evolution — Ichthyornis dispar, a tern-sized seabird from the Late Cretaceous of Kansas. It had a keeled breastbone and strong wings like modern birds, but still carried teeth in its jaws. | Arianna D. Lord / Yale Peabody Museum (specimen YPM VP 001450) | CC0 1.0 | Link ↗ |
| Evolution — Confuciusornis, from the Early Cretaceous of north-eastern China, is one of the earliest known birds with a toothless, horny beak; it still had large claws on its wings. Many fossils of it have been found, often with feathers preserved as dark films. | Naturalis Biodiversity Center, Leiden (specimen RGM.631750) | CC0 1.0 | Link ↗ |
| Evolution — A museum model (not original fossil bone) of the skull of Phorusrhacos longissimus, a flightless 'terror bird' from the Miocene of Patagonia, Argentina. Phorusrhacids were large ground predators with tall, hooked beaks. | Marilyn Fox / Yale Peabody Museum (YPM VPPU 016044) | CC0 1.0 | Link ↗ |
| Evolution — Lower jaw of Gastornis (formerly Diatryma) gigantea from the Eocene Wasatch Formation of Wyoming. The extraordinarily deep jaw belonged to a giant flightless bird; the smooth white tip is a modern restoration, not fossil bone. | Yale Peabody Museum, Division of Vertebrate Paleontology (specimen YPM VP 006352) | CC0 1.0 | Link ↗ |
| Evolution — Egg of an elephant bird (Aepyornis) from Toliara, south-western Madagascar. Elephant birds were giant flightless ratites that survived until roughly a thousand years ago; their eggs are among the largest laid by any known animal. | Lucie Goodayle / © The Trustees of the Natural History Museum, London (specimen NHMUK PV A 3289) | CC BY 4.0 | Link ↗ |
| Evolution — Owen's 1879 plate compares the femur, tibia and hind-toe claw of Haast's eagle (Harpagornis moorei; large bones and the big claw at lower right) with the bones and claws of a wedge-tailed eagle and a harrier. Haast's eagle, the largest known eagle, hunted moa in New Zealand until about 600 years ago. | J. Erxleben (lithograph from photographs), printed by M. & N. Hanhart; Plate CVII in Richard Owen, Memoirs on the Extinct Wingless Birds of New Zealand, vol. 2 (London: John van Voorst, 1879). Scan: Auckland War Memorial Museum Library via Biodiversity Heritage Library / Internet Archive, 1879 | Public Domain | Link ↗ |
| Evolution — Owen's 1879 plate of a Dinornis robustus skeleton, with breastbone and pelvis details and a scale in feet. Owen gave this restored skeleton a height of about 8 ft 6 in (2.6 m) with the neck stretched up; moa had no wing bones at all. | J. Erxleben (on stone; 'R. Owen del.'), printed by M. & N. Hanhart; Plate XCVI in Richard Owen, Memoirs on the Extinct Wingless Birds of New Zealand, vol. 2 (London: John van Voorst, 1879). Scan: Auckland War Memorial Museum Library via Biodiversity Heritage Library / Internet Archive, 1879 | Public Domain | Link ↗ |
| Evolution — The type specimen of Tympanonesiotes wetmorei, a foot bone from the Miocene of South Carolina. It belongs to the bony-toothed birds (Pelagornithidae), the family of Pelagornis: huge soaring seabirds whose jaws bore tooth-like spikes of bone. | Michael Brett-Surman / Smithsonian Institution, National Museum of Natural History (specimen USNM V 16809) | CC0 1.0 | Link ↗ |
(05) Limitations
What this atlas is not
- The food webs and simulator are teaching models of documented relationships, not predictive population models.
- Distribution maps show countries or continents of occurrence, not detailed range maps. Consult BirdLife International or eBird for those.
- Red List assessments are periodically revised; the year shown tells you how current each one is.
- Live data services (eBird, Macaulay Library, the IUCN API) are not connected: they require API keys and their media are not openly licensed for reuse. All content is bundled locally so the site works without them.
- Typefaces: Inter and Inter Tight (SIL Open Font License), self-hosted.