From Mexican Ducks to Green-winged Teals, a new global bird list tackles the problem of 'taxonomic anarchy.'
A consortium of global bird experts, chaired by Southern Cross University ornithologist Professor Les Christidis, released a definitive list of the world's birds today, in an effort to improve identification and conservation outcomes worldwide.
AviList is a single list of the world's 11,131 species of birds, classified within 252 families. It is the result of four years of consultation – and at times vigorous debate – between global experts in taxonomy, nomenclature, and bioinformatics.
Consolidating previous global bird species lists, AviList signals a new era in global bird taxonomy, with implications for conservation and protected species legislation across the planet.
"Taxonomy is full of problems that need solving," said Professor Christidis , a world expert on Australian birds and also Pro Vice-Chancellor (Research Infrastructure) at Southern Cross University.
"Taxonomic anarchy has always been a problem for conservation. Take the albatross for example, which is a threatened species in many areas that are dependent on fisheries and other industries. There were anywhere between 13-26 species of albatross, depending on which list you consulted.
"If different agencies involved in conservation of biodiversity use different names, then not only is there the chance of misalignment of resources, but also confusion on what needs to be protected. AviList provides a new level of rigorous and transparent governance and guidance," he said.
The global consortium of ornithologists and taxonomists from 11 different institutions, including the Cornell Lab of Ornithology at Cornell University, BirdLife International, the International Ornithologists' Union and Southern Cross University, worked with a master list of more than 11,000 species drawn from three previous global references: Clements, International Ornithological Congress and BirdLife International checklists.
Meeting regularly across different time zones, the group looked at morphology (what a species looks like), behaviour, ecology, genetics, phylogenetic relations (species relationships on an evolutionary tree), time since divergence based on genetics, biogeographical distributions, and any evidence of reproductive isolation.
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Their research ranged from the analysis of evolutionary trees to sound recordings of breeding songs, inspecting museum specimens for plumage differences, and considering the latest DNA research via genome sequencing.
"It's work, but it's fun," said Pam Rasmussen, one of the Cornell Lab scientists on the working group, who has studied the taxonomy of Asian birds for many decades.
"Evolution is a work in progress."
AviList is free to download and can be used by ornithologists, birders, biologists, conservation practitioners, administrators, legislators, and any other stakeholders in bird classification. The scientists plan to review it annually.
AviList: The Global Avian Checklist © 2025 by AviList Core Team is licensed under CC BY 4.0
