Taxonomic evolution

After what had seemed like a lengthy free-for-all over bird classification and the order in which species should be presented in books and lists, things had begun to settle down somewhat in the 1890s with the detailed researches of Max Fürbringer in Germany and German-born Hans Gadow in Cambridge, England. Gadow’s system was based on an analysis of about 40 largely anatomical characters and his classification started with the Ostrich Struthio camelus, and finished with the passeriformes, about which he had comparatively little to say. The Gadow system, and the passeriform classification constructed by Sharpe (1899–1909) laid the foundations for many later revisions and versions.

By the nineteenth century British Henry Seebohm (1881) listed the thrushes as the most highly developed among the birds on account of their singing qualities and the development of the plantar tendons. British Alfred Newton (1893, a founding member of the British Ornithologists’ Union) disagreed, and later arrangers from the Norway-born American ornithologist Leonhard Stejneger to the German Erwin Stresemann have listed the crows and their allies as the highest group of the Oscines.

In 1930, Alexander Wetmore, working at the Smithsonian Institution in Washington, DC, published the first of five editions of a classification based heavily on that of Gadow as successively modified. This was adopted by the AOU (American Ornithologists' Union) for their checklists and became widely used throughout the world (even in 1969 in East Germany). Wetmore’s sequence in 1930 started with the non-passerines and ended with the finches and buntings.

Fifty years ago, the Fringillidae were regarded as the most recently evolved birds 25~30 million years ago (Oligocene), when seed-bearing plants suddenly came into prominence. The disconnected families Emberizidae (OLD WORLD BUNTINGS) and Passerellidae (NEW WORLD SPARROWS) evolved hereafter, with later New World Cardinalidae (CARDINALS, GROSBEAKS) and Thraupidae (TANAGERS) spin offs.

Peters Check-list of Birds of the World (1931 to 1987)

James Lee Peters (a friend of Wetmore) was the initiator of the monumental work Check-list of Birds of the World, which was published at Harvard University, Cambridge, MA, in 16 volumes during the over-fifty years period from 1931 to 1987 (most Passerines in the continuation from 1960 by the later (mostly) U.S. authors E. Mayr, H.G. Deignan, A.L. Rand (Canadian), J. Delacour (French-born), J.C. Greenway, R.A. Paynter, C. Vaurie (French-born), J. Davis & A.H. Miller, S.D. Ripley, R. Schodde (Australian), D.W. Snow (British), F. Salomonsen (Danish), R.E. Moreau (British), R.W. Storer, G.H. Lowery, E.R. Blake, M.A. Traylor, S. Amadon), and has been highly influential in ornithology (and used as a basis for practically all modern check-lists). The order of families now chosen ends with birds-of-paradise and corvids and was following Mayr and Greenway (1956) in what has become known as the Basel sequence, agreed by a European sub-committee for use by European editors. The Peters’ list was the first to introduce subspecies, and was adopted in 1971 by the BOU, but BOU reverted to its 1952 (Wetmore order) Check-list after the local bird recorders expressed their desire for stability.

With the Peters Checklist far from complete in the 1960s, ornithologists were itching to compile their own, which lead in 1974 to the Birds of the World Checklist by James F. Clements, A Coded List of Birds of the World (typed) by Ernest P. Edwards (1974, Sweet Briar, VA), An annotated list of the birds of the world (typed) by Mr. Joseph G. Griffith and Mr. Michael A. Cunningham (1974, Monrovia, CA), and the Checklist of The World’s Birds by Edward S. Gruson (1976, New York, NY). In Brighton, Sussex, United Kingdom, D. T. Holyoak did a try with presenting A hand-list of the bird species of the world (1975), but only the Order Anseriformes was published, intended to seek the advice of specialists. In this pre-digital era, the last two publications showed alphabetical listing of species within genera, and the British issue of genera within families as well.

List of Recent Holarctic Bird Species (1973, 1977, reprints in 1980 and 1991)

Karel Hendrik Voous (Amsterdam) published his list of recent holarctic bird species from 1973 to 1977 at Rothshild's private Natural History Museum in Tring, Hertfordshire. It was based on the Wetmore order but incorporated many of the more recent research results, and was thus not too unfamiliar. It was adopted by the nine-volume The Birds of the Western Palearctic ornithological handbook, and from 1978 by the BOU (British Ornithologists' Union). The list has been reprinted twice, in 1980 and 1991. The rapid and widespread acceptance of Voous’s work assured the continuation of a period of taxonomic stability in Europe that lasted into the 1990s. Voous’ list was also used for the Handbook of the birds of Western Palaearctic (Cramp and Perrins, 1994).

Earlier, the BOU had followed Ernst Hartert, a German ornithologist, who worked in Tring, and had devised his own system based on Gadow and Sharpe, but starting with the passerines.

Even in the 2000 Sri Lanka photographic guide (new Holland publisher), the standard sequence of Orders and Families by Voous is still maintained, as it was at the Association of European Rarities Committees (AERC), published in 2003 and finally updated in July 2015.

Reference list of the birds of the world (1975)

The 1975 edition of the Reference list of the birds of the world by J.J. Morony Jr., W.J. Bock & J. Farrand Jr., compiled to inventory the anatomical collection of the American Museum of Natural History, at a time that Peters’ Check-list was not completely published, and without mention of English names, geographic ranges and subspecies. Peters’ Check-list (volume 1 to 15) was the basic reference. Ernst Mayr made a partly completed manuscript copy available for volumes 8 and 11 that were yet unpublished.

This (typed) Reference list of the birds of the world (“widely used” in 1981) has also been adopted for some BOU’s non-European check lists. In North America, where the Birds of the World Checklist by James F. Clements (a well-traveled amateur birder) was available since 1974, primarily intended for the birding community, and initially not recommended by the professional ornithologists, who then apparently decided to compile the above mentioned Reference list with help from James C. Greenway Jr. and Dean Amadon, as well as David W. Snow and Melvin A. Traylor, Jr.

Howard and Moore Complete Checklist of the Birds of the World (1980~1994)

Richard Howard (non-Passerines) & Alick Moore (Passerines), themselves seemingly not professional ornithologists either, released their Oxford University Howard and Moore check list Complete Checklist of the Birds of the World in 1980 (started in 1972) for the use of both amateur and professional ornithologists (the first complete list to include subspecies), largely based on Peters’ list (also following order of families by Ernst Mayr), but with the non-Passerines published by Peters in the 1930s, the Herons are mainly based on later publications by J. Hancock & H. Elliott (British) and W.J. Bock, as well as the Storks (by M.P. Kahl), Waterfowl (by P.A. Johnsgard and J. Delacour), Eagles, Hawks and Falcons (by L. Brown & D. Amadon), Curassows (by J. Delacour & D. Amadon), Grouse (by P.A. Johnsgard), Pheasants (by J. Delacour), Rails (by S.D. Ripley), Plovers (by W.J. Bock), Sandpipers (by J.R. Jehl), Gulls, Skuas and Auks (by W.B. Alexander), Pigeons and Doves (by D. Goodwin, British), Parrots (by J.M. Forshaw, Australian), Toucans (by J. Haffer, German) and Ovenbirds (by C. Vaurie). K.H. Voous’ publications were, among many others, used for Grebes, Petrels and Shearwaters, Buntings and Finches. C.G. Sibley’s early work contributed to Flamingos, Thrushes, Monarchs, and Wood Warblers.

Peters’ Check-list was not used at all for Turacos (R.E. Moreau), Swifts (British R.K. Brooke, C.M. N. White, American R. Meyer de Schauensee), Bee-eaters (British C. Fry), Cotingas and Manakins (D.W. Snow), Tyrant-Flycatchers (C.B. Cory, Austrian C.E. Hellmayr and R. Meyer de Schauensee), New Zealand Wrens (O.S.N.Z.), Asities (A.L. Rand, Canadian), Lyrebirds and Scrubbirds (R. Schodde, Australian), Hawaiian Honeycreepers (G.C. Munro, New Zealand born American), Birds of Paradise and Bowerbirds (American W.J. Cooper & J.M. Forshaw, Australian), Crows (D. Goodwin, British).

The Reference list of the birds of the world by J.J. Morony was quoted for the Woodpeckers, Pittas, Monarchs, as well as Old World Warblers and Flycatchers (also quotations by C. Vaurie) and Australasian Wrens (also quotations by R. Schodde).

Over 70 non-Passerine families have been quoted mainly from Peters’ work, and over 40 Passerine families from his work and the later authors. This Howard and Moore check list soon became the most popular in English in Europe, as a world check list.

In the 1990/1991 second edition of the Howard and Moore check list (actually the third edition since 1980 after a 1984 upgrade), the species count came in at just over 9200 (vs 8500 in 1980) due to changes in the recognition of species limits, i.e. upgrading/splitting subspecies into full species, while just 34 new species were described. This is in contrast with what was common usage until the 1970s when ”lumping” of species reduced them to subspecies.

But a 1994 reprint included an appendix with a further 282 changes, among which 150 splits/upgrades, 30 lumps and 50 scientifical name changes (36 genus and 14 specific name) and 21 newly discovered (of which 11 before 1991), adding another 130 species. 9,360 species were recognised. This should have been called the third edition but wasn’t.

Wolters’ Die Vogelarten der Erde (1975~1982)

For the classification of birds according to German-language names there was around 1970 no other work than the three bird volumes of the animal encyclopedia Grzimek’s Animal Life (Zurich, Switzerland). The co-editors of these volumes 7 to 9, which appeared in 1968-1970, largely took over the classification of Peters and updated it according to the state of knowledge at the time. But this work is primarily a description of the birds and only provides an incomplete accompanying classification.

In 1982 Hans Edmund Wolters’ Die Vogelarten der Erde, the Birds of the Earth (Hamburg/Berlin), was initially published in seven partial deliveries, of which the first appeared in 1975. Up to this point it was the only independent classification with German bird names. With the division into 50 orders and 225 families however, this classification differs considerably from the classifications discussed above. Columbiformes contained 7, and Psittaciformes 11 separate families, while all thrushes were directly within Muscicapidae, and not in a subfamily Turdinae.

Since, according to Wolters' view, ordinal names should be adapted to the names of the typical families, Anseriformes is called Anatiformes and Galliformes becomes Phasianiformes. Nine families (also) occurring in the Palearctic region are, in contrast to Peters, Wetmore et al., raised to orders, namely the Otidiformes, Ralliformes, Turniciformes, Lariformes, Alciformes, Pterocliformes, Accipitriformes, Upupiformes and Alcediniformes, not following the ICZN code (International Commission on Zoological Nomenclature).

A World Checklist of Birds by Burt L. Monroe, Jr., and Charles G. Sibley (1993)

One major attempt to rework the higher-level classification (and sequence) of birds following Sibley & Ahlquist 1990 (pioneering DNA-DNA hybridisation studies by the early 1970s in at the Yale University in New Haven, CT) has been resisted because of uncertainties over the data and its analysis. The Sibley ‘tapestry’ (as his massive phylogeny of birds became known) was one of the first major attempts to create a truly new classification since Fürbringer and Gadow in the 1890s. Parts of the tapestry have since been confirmed or reworked using other techniques, and the more robust conclusions have started to be adopted.

These early techniques have been replaced by newer ones based on mitochondrial DNA sequences and molecular phylogenetics approaches that make use of computational procedures for sequence alignment, construction of phylogenetic trees, and calibration of molecular clocks to infer evolutionary relationships.

In 1993 the Sibley/Monroe checklist first appeared under as A World Checklist of Birds, with the Whistlers (Thickheads), Vangas, Orioles, Drongos, Monarchs, Birds of Paradise and Cuckooshrikes all within Corvidae, Babblers within Sylviidae, Wrens and Gnatcatchers within Certhiidae, Mockingbirds within Sturnidae, Flowerpeckers within Nectariniidae, Weavers, Accentors, Indigobirds, Wagtails, Pipits and Waxwings within Passeridae, Chats and Robins, but also Thrushes (Turdinae) within Muscicapidae, New World Sparrows, Wood Warblers, Blackbirds, Cardinals and Tanagers within Fringillidae. It is worth mentioning that the Sibley/Monroe checklist does not list subspecies, with the exception of those under discussion, as separate species to be raised. A total of 9,700 species are listed.

By 1996, this checklist was for a while used for the Indian and Indochinese region, but later on the more traditional order and family layout was adopted.

Birds of the World, a Check List by James F. Clements (1991 up to now)

The 1991 4th Clements Birds of the World Checklist made use of ‘Distribution and Taxonomy of Birds of the World’ by Charles Sibley and Burt L. Monroe, Jr., though it followed the higher-level taxonomy (i.e. Orders and Families) set forth by Dr. Frank Gill in his ORNITHOLOGY (1990, New York, NY). It was now published by Ibis Publishing Company (Vista, CA), set up by Clements.

The 2000 5th Clements Birds of the World Checklist (designated as the “official world checklist” of the American Birding Association and newly including subspecies) has been changed from previous editions to mirror that of the Handbook of the Birds of the World series (Lynx Edicíons, Barcelona, 1992), sponsored by BirdLife International (a Cambridge, UK based global partnership of conservation organisations that strives to conserve birds). Handbook of the Birds of the World base sequence was intended to follow that of Morony, Bock and Farrand (Reference List of Birds of the World, 1975, American Museum of Natural History), with Walter J. Bock as the consultant for systematics and nomenclature. One of the most valuable things about HBW is that sufficient information is put at our disposal to enable even lay readers to follow such disputes and even to form their own opinion.

This Clements Checklist was adopted in Asia as well at the turn of the century. The 2007 edition was published by Cornell University Press (Ithaca, NY), and a digital update included a comprehensive list of species having different common names in the Clements and IOC lists.

The Clements Checklist is now used by eBird, an American-born online database of bird observations. By 2018, in the New World, the Clements Checklist largely defers to the two AOS committees–the North American Classification Committee (NACC) and the South American Classification Committee (SACC)–with the goal of near-complete compliance. By now, all taxonomic and nomenclatural decisions of the AOS, maintained by a democratic member process, are automatically recognized by the ABA-CLC (American Birding Association Checklist Committee).

In addition to the formal taxonomic concepts that are included in the Clements Checklist, the eBird taxonomy includes an expanded list of other bird taxa that birders may report. Since eBird is becoming increasingly popular, more non-American birders e.g. in Asia/China, are now switching to Clements.

Howard and Moore Complete Checklist of the Birds of the World (2003~2014)

The 2003 3rd edition Howard and Moore check list (cut-off date for incorporation of new material: 31 December 2000), again by Academic Press, and in America published at Princeton University Press, New Jersey, was edited by the British ornithologist Edward C. Dickinson, who handled Asia, supported by the Americans David Pearson (Africa) and James Van Remsen Jr. (the Americas, and founder of the South American Classification Committee, also member of the AOU Committee on Classification and Nomenclature), Dutchman Cees S. Roselaar (Palearctic) and Australian Richard Schodde. The birds were not classified according to order, which is rather unusual for a classification list. Likewise, some genera are not assigned to any family, as the assignment was not clear for the team of authors. The sequence in which birds are listed is now meant to reect their evolution. If one were to draw an evolutionary tree of birds, those families that branch off earliest (i.e. are the most ancient) should be listed rst. 9,723 species were recognised.

It is worth notifying that more than a quarter of the species that were upgraded (split) to species from previous subspecies in the 1994 H&M edition, now were lumped back to subspecies level. Two-thirds of these species were erected by Sibley & Monroe in their 1990 list that was without subspecies. 1 out of 6 would be definitely lumped back in 2003, three-quarter consisting of species introduced by Sibley & Monroe.

Thirty species that were lumped by 1990, were brought back to species level later on.

Andrew W. Kratter in The Auk (The American Ornithologists' Union), Volume 122, Issue 2, 1 April 2005, Pages 712–714: “Checklists produced in the interlude between Peters and Dickinson fell short for a number of reasons, including out-of-date classifications, lack of subspecific treatment, overly novel classification schemes, and partial to complete lack of references. Justifications for taxonomic treatments have been all but absent in those volumes, especially at levels other than species.” But even in the Introduction of the 2003 H&M edition, it is said that a subspecies of the relevant volume of Peters Check-list was listed even if no subsequent evaluation of the hypothesis could be traced.

Edward C. Dickinson also compiled the 2013 (non-Passerines) with help from James Van Remsen Jr. and the 2014 (Passerines) edition, with help from Leslie Christidis from Australia. Both volumes had support from The Natural History Museum (UK) and from the American Museum of Natural History. This edition was published by Aves Press Limited. The list sequence began to reflect the findings from studies of avian DNA. This fourth edition of The Howard and Moore Complete Checklist of the Birds of the World has been updated to reflect the considerable change in the understanding of the evolution of birds derived from the study of their DNA over the past decade; thus the Cracraft sequence, adopted in 2003, is completely revised here. With 10,027 extant species recognised, this edition again drew upon the expertise of regional consultants. Cracraft is writing, that we are approaching the time, that the avian systematic community will need to consider to breaking up the “Passeriformes” into multiple orders.

At this stage, a quarter of the species that were upgraded/split from previous subspecies in the 1994 H&M edition, were lumped back, while 11% of the ex-subspecies (40% of the lumped ones) were upgraded/split again by 2013 at H&M, half consisting of species introduced by Sibley & Monroe. The upgraded/split species that were kept so consisted for one-third of species introduced by Sibley & Monroe.

Seventy-nine species that changed the genus name by 1990, received the initial 1980 name back at Howard and Moore later on.

By 2006, at both the Natural History Museum in London and Tring, and the American Museum of Natural History in New York, the bird collection curators were happy to use the Howard and Moore Complete Checklist as a regular working tool.

The South American Classification Committee, founded in 1998, is an official committee of the American Ornithological Society (the former American Ornithologists' Union). The mission of this committee is to create a standard classification, with English names, for the bird species of South America. The Howard and Moore checklist (Dickinson 2003 and 2013/2014) provided the base list for the SACC.

However, the 2013/2014 Howard and Moore checklist apparently will be the last: in 2015 it was stated that a next edition would be edited by Les Christidis, but in August 2018 he resigned. Proposed updates weren’t released either.

But even now, the writers of The Largest Avian Radiation (2020, Lynx Edicíons), generally follow this Howard and Moore check list in respect to their taxonomic overview.

BirdLife International/Handbook of the Birds of the World (BirdLife/HBW)

At the same time, that the Howard and Moore checklist became history (looking back), Lynx Edicíons and BirdLife International published the first ever Illustrated Checklist of the Birds of the World (for non-passerines) in 2014 and the second volume (for Passerines) in 2016, when BirdLife/HBW adopted and adapted a new species assessment method, now relying more on visual, vocal and behavioral differences to define species than other authorities, and less on genetic differences (which it still considers), possibly partly due to the relative failure of the DNA-DNA hybridization method.

“To assess when newly described species or proposed splits make sense, BirdLife/HBW is making use of systematic criteria, involving weighting morphological and acoustic differences as compared with the nearest believed relative, particularly intended to help make decisions regarding species that are geographically isolated from each other.

Following Joseph A. Tobias (2010, University of Oxford, UK), preliminary tests show that these criteria result in relatively few (5%) changes to avian taxonomy in Europe, yet are capable of extensive reassignment of species limits in poorly known tropical regions. While we recognize that species limits are in many cases inherently arbitrary, we argue that our system can be applied to the global avifauna to deliver taxonomic decisions with a high level of objectivity, consistency and transparency.”

This method is disputed scientifically but eminently pragmatic. The Scandinavian writers of the classification chapter in The Largest Avian Radiation (2020), issued by Lynx Edicíons, the earlier HBW publisher, state that a scoring system, based on distinctness, is not, in principle, much different from the way in which taxonomy was practised 100 years ago. The approach specifically ignores genetic data in defining species and some recommendations are in disagreement with genetic population structure, while it does not take into account the fact that speciation dynamics differ between Europe and the lower altitudes. Following Van Remsen (2015), HBW suffers a lack of avian speciation scientists. The Howard and Moore checklist is mentioned as one of the sources.

BirdLife/HBW is followed by the International Union for Conservation of Nature (IUCN) for the Red List of Threatened Species. Prior to the publication of the first volume of this BirdLife/HBW Checklist, BirdLife published an annually updated taxonomic checklist since 2007 based on the taxonomies followed in a number of regional lists, often relying on Sibley & Monroe.

IOC World Bird List (from 2007)

Since 2007 we have the digital IOC World Bird List by F. Gill & D. Donsker, which is an open access resource of the international community of ornithologists. Its primary goal is to facilitate worldwide communication in ornithology and conservation based on an up-to-date evolutionary classification of world birds and a set of English names that follow explicit guidelines for spelling and construction. Though improved alignment and unification with the other independent taxonomic works initially was set as a goal of the International Ornithologists Union (Baton Rouge, LA), that started with a Round Table discussion at the 2018 congress in Vancouver, BC, but that was before the cease of the Howard and Moore checklist, and the merger of BirdLife/HBW and Clements/eBird. The website project maintains an informal affiliation with the IOU (International Ornithological Union, formerly known as the International Ornithological Committee) and retains the well-established IOC name, a possible acronym for the International Ornithological Community.

The first International Ornithological Congress meeting was held in 1884, the next will be held in Durban, South Africa after 4 years, in 2022.

From December 2017, the BOU follows the IOC World Bird List, accompanied by a vast number of people worldwide, (a smaller proportion in North America, though), and it has been adopted by the latest 1,000-page photographic guide book in China by Zhao Xinru.

Higher level taxonomy: evolutionary sequence in time, intelligence, or colour?

Regarding the sequence of bird families, Peters adopter the Wetmore order, ending with the Icteridae, Thraupidae and Fringillidae (then incl. Emberizinae), but Mayr and Greenway, appointed by the Harvard University in Cambridge, Massachusetts, chose in 1956 to follow the even arbitrary European-agreed sequence ending with the Bowerbirds, Birds-of-Paradise, Corvids, which was copied by Howard and Moore (and Morony), thereby apparently considering the crows’ intelligence more important than their instinct.

In 2020, neurobiologist Andreas Nieder of the University of Tübingen in Germany found that “crows and probably other advanced birds have sensory awareness, in the sense that they have specific subjective experiences that they can communicate. Besides crows, this kind of neurobiological evidence for sensory consciousness only exists in humans and macaque monkeys.”

Ernest Thomas Gilliard’s (1958) Living Birds of the World, the first coffee table bird book, that was also widely known in Europe (translated into German, French, Spanish, Italian, Dutch), adopted Wetmore but placed the Ploceidae at the end.

The Spanish Handbook of the Birds of the World, starting in 1992, initially was to cover 12 volumes ending with the Finches to Crows (à la Morony/Peters), but after it was decided at the turn of the century to expand the series to 16 volumes, the last volume (2011) featured the Tanagers to new World Blackbirds, i.e. Thraupidae, Cardinalidae, Emberizidae, Icteridae. Volume 15 ended with the Fringillidae and Parulidae.

By 2003, Howard and Moore used the Cracraft sequence, ending with the Turdidae, Muscicapidae, Cinclidae, but in 2013, this order was vice versa. With Clements in 1991 ending with Fringillidae, Parulidae, Emberizidae (incl. Cardinalinae and Thraupinae), Icteridae, following Dr. Frank Gill until 2009, as did IOC until 2017, both by 2018/2019 adapted the evolutionary sequence of Icteridae, Parulidae, Mitrospingidae, Cardinalidae, Thraupidae following the new phylogenetic taxonomy provided by Frederick Keith Barker et al. (2013, 2015, University of Minnesota, St. Paul, MN and initiator of resurrecting Icteriidae), as did BirdLife/HBW for the last three families.

H&M (2014) counts some 10,000 extant species, while the numbers at Clements, IOC and BirdLife/HBW currently vary between 10,500 and 11,000.


So, at the time that the American Peters’ Check-list was finished in 1987, only the British Howard and Moore check list, based on it as well as on the American Morony’s Reference list of the birds of the world, itself also based on Peters, practically was the world’s standard over the last 40 years, from 1980 on.

This happened 50 years after this role was meant to be fulfilled by Peters Checklist, which today is largely outdated with regard to the classification of bird species into families and genera, but is still in use because of the description of the species and subspecies, which is based on literature citations.

The 1974 American Clements Birds of the World Checklist was primarily intended for the birding community, then, by 1991 relied on Sibley and Monroe’s partly tentative DNA-DNA hybridization achievements, after which it switched to Spanish Lynx’ Handbook of the Birds of the World. Up to 2007, Clements’ list was still omitting all aspects of authorship or citation, making taxonomic decisions impossible to track or verify, but thereafter update change references were included.

In 2020 the exclusive digital rights to all the content of Handbook of the Birds of the World were acquired from Lynx Edicíons by the Cornell Lab of Ornithology (Cornell University, Ithaca, NY), with John W. Fitzpatrick (*1951, USA) as director, and Irby Lovette (*1969, USA and initiator of the Mitrospingidae, Nesospingidae and Spindalidae families) as director of the ‘Fuller’ Evolutionary Biology Program (2015 gift by Larry Fuller, who was a star pitcher for the Cincinnati Reds baseball team: “We thought this would be a great way to be sure the absolutely top scientists are attracted to the Lab of Ornithology”). Birds of the World (BOW) is a powerful online research database that is striving for scientific consensus between the BirdLife/HBW taxonomy and the Clements taxonomy.

Though superorders and other lineages above the order level (in non-passerines) and below the order level (in passerines) are not mentioned, the IOC World Bird List in the meantime seemingly deserves the title of the world’s standard, with renowned ornithologists as advisers, such as Per Alström (*1961, Sweden), Jon Fjeldså (*1942, Norway, working in Denmark), Alan P. Peterson (*1953, USA), Douglas Pratt (*1944, USA), Robert S. Ridgely (*1946, USA), Nigel Redman (*1952, United Kingdom), George Sangster (*1970, the Netherlands, also working in Sweden), Frank Rheindt (*1977, Germany, working in Singapore) and Richard Schodde (*1936, Australia).


Sources: publicly accessible internet sites
A complete checklist of he Birds of the World, Richard Howard and Alick Moore, Oxford University Press, 1980

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September 2021