The project to develop The Global Avian Checklist (AviList) began in 2016. At the time, three major global bird lists were being updated regularly, including the IOC World Bird List managed by the International Ornithological Congress (IOC). The aim of the AviList project was to harmonise bird taxonomy, scientific names, and English names to create a single reference checklist.

More information about the project can be found here: The Global Avian Checklist.

On June 11 2025 the first version of the AviList was formally launched. You can download the list from the AviList website here: The Checklist v2025.

AviList Core Team. 2025. AviList: The Global Avian Checklist, v2025. https://doi.org/10.2173/avilist.v2025

The list will be updated once a year.

The IOC bird list is hosted on a dedicated World Bird Names website. The list has most recently been updated twice a year, usually in January and July. The current version of the IOC bird list is v15.1, released February 28 2025.

This blog post provides a summary of how AviList v2025 differs from IOC bird list v15.1. At present, only a detailed analysis at Order/Family level has been completed, although some indications of how species are being treated is also provided.

New Orders

Family: Cathartidae – New World Vultures has been moved from Order ACCIPITRIFORMES to new order CATHARTIFORMES.

Family: Galbulidae – Jacamars and Family: Bucconidae – Puffbirds have been moved from Order PICIFORMES to new order GALBULIFORMES.

Revision of families

There are 255 families of extant species in the IOC bird list v15.1.

In the AviList, this number has been reduced to 251 through the following changes:

Family: Bucorvidae – Ground Hornbills has been embedded within Family: Bucerotidae – Hornbills

Family: Scotocercidae – Streaked Scrub Warbler has been embedded within Family: Cettiidae – Bush Warblers and Allies

Family: Alcippeidae – Alcippe Fulvettas has been embedded within Family: Leiothrichidae – Laughingthrushes and Allies

Family: Icteriidae – Yellow-breasted Chat has been embedded within Family: Icteridae – New World Blackbirds, Troupials, and Allies

Of the 251 families, more than a third have an English name that is different from the English name in the IOC bird list v15.1. Some of these changes simply replace ‘&’ by ‘and’, or insert ‘and’ instead of a comma.

One family has a modified scientific name. This is Family: Eulacestomatidae – Ploughbill.

Resequencing of Non-Passerine Orders

There are 45 Non-Passerine Orders in the AviList.

Compared to the IOC bird list v15.1 (43 Non-Passerine Orders), the most significant changes in the sequencing of Orders are as follows:

Order PHOENICOPTERIFORMES (Flamingos) is moved from position 22 to position 8.

Order PODICIPEDIFORMES (Grebes) is moved from position 21 to position 9.

These moves place the two Orders at the beginning of the subclass NEOAVES (TYPICAL BIRDS).

The following Orders have been moved from the beginning of NEOAVES to occupy positions mid-way through the sequence of Non-Passerine Orders:

Order CAPRIMULGIFORMES (Nightjars)
Order STEATORNITHIFORMES (Oilbird)
Order NYCTIBIIFORMES (Potoos)
Order PODARGIFORMES (Frogmouths)
Order AEGOTHELIFORMES (Owlet-nightjars)
Order APODIFORMES (Treeswifts, Swifts, Hummingbirds)

The other big mover is Order OPISTHOCOMIFORMES (Hoatzin), which is relocated from position 32 to position 16.

Resequencing of Passerine families

The standout changes in the sequencing of Passerine families include the movement of two blocks of families to positions farther down the structure. There are 144 Passerine families in the AviList (147 in IOC bird list v15.1).

Families Cnemophilidae – Satinbirds, Melanocharitidae – Longbills and Berrypeckers, Notiomystidae – Stitchbird, and Callaeidae – New Zealand Wattlebirds have been moved from positions averaging 33 in the sequence to positions ranging from 61 to 64.

Families Dulidae – Palmchat, Bombycillidae – Waxwings, Ptiliogonatidae – Silky-flycatchers, Hylocitreidae – Hylocitrea, and Hypocoliidae – Hypocolius have been moved forward by a similar amount to immediately precede Family: Regulidae – Kinglets.

Only one family has been moved significantly in the other direction. Family: Hyliotidae – Hyliotas is relocated from position 107 to position 70 in the sequence.

Also of note is the reordering of the 13 families that make up the New World Suboscine Passerines (excluding Sapayoa). Their sequence has largely been reversed, with Family: Pipridae – Manakins appearing first and Family: Furnariidae – Ovenbirds and Woodcreepers coming last.

Species overview

Within some families, there has been a wholesale resequencing of species. Others have been subject to a partial resequencing.

Both the English and scientific names of species appear to align well with those in IOC bird list v15.1. However, there are some instances where species have been ascribed to a new or different genus, or have a new species epithet. An example would be 11 Fruit Doves that have been moved from genus Ptilinopus to new genera Megaloprepia and Ramphiculus.

The AviList will be used as the basis for 2026 editions of ATWB Companion Guides. Work has begun on the implementation of the extensive changes involved. Some 2026 editions will be released in late 2025, while others may be delayed to sometime during 2026.

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Some details …

Each of the ATWB Companion Guides has a number of important features, including:

– A complete taxonomic listing of bird species

– An indication of where each bird family and species can be found in its native state

– Spotlighted species that have a restricted regional or worldwide range

However, perhaps the key feature of all eBooks in the Companion Guide series is the way you can quickly and simply access relevant, up to date online information about every featured bird species. If your reading device is connected to the internet, a single click will take you to a search results page for a species, from where you can continue to search for additional information to whatever level of detail you desire.

Until 2025, the ‘All the World’s Birds’ series of Companion Guides derived its taxonomy, English names and scientific names from The IOC World Bird List, an open access resource maintained by the International Ornithological Congress (IOC). The IOC bird list is hosted on a dedicated World Bird Names website, which provides access to the list in various different formats.

The version of the IOC bird list used in the ‘All the World’s Birds 2025’ series of Companion Guides is Version 14.2, published August 21 2024.

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