"Wisdom begins with putting the right name on a thing"
(Old Chinese Proverb)

Updates of IOC Classification (2.0)

UPDATES OF CLASSIFICATION (VERSION 2.0)

Version  2.0 of the IOC World List included the  first substantial updates of the  higher classification of the birds of the world. Summarized below are the major features of the 2.0 updates, and supplements:

  1. Separation  of 9 (+1) additional Orders, bringing the total recognized to 40 (details below)
  2. Separation  of 8 (+2) additional families of nonpasserine birds, and 25 (-1) families of passerine  birds (4 [-1]suboscine, 21 oscine), bringing the total number of families  (excluding 7 incertae sedis) recognized to 224 (details below).
  3. Resequencing of families of suboscine passerines to  match the sequence of these families in the SACC classification, and  reorganization of the Old World warbler taxa, but we defer major sequence  changes to a future update.
Orders
Phaethontiformes Tropicbirds
Suliformes (v2.5) Frigatebirds, boobies, cormorants, anhingas
Falconiformes Falcons
Otidiformes Bustards
Mesitornithiformes Mesites
Cariamiformes Seriemas
Eurypygiformes Kagu and Sunbittern
Pteroclidiformes Sandgrouse
Leptosomiformes Cuckoo-Roller
Bucerotiformes Hoopoes and hornbills

NOTE:  We refrain from adding Cathartiformes (New World vultures) and Galbuliformes  (jacamars and puffbirds) adopted by Clements 6.1.

Nonpasserine  families

The   families of nonpasserine birds added to the list are

Sagittariidae Secretarybird
Pandionidae Osprey
Pluvianellidae Magellanic Plover
Pluvianidae Egyptian Plover
Strigopidae (formerly Nestoridae) New Zealand parrots
Cacatuidae Cockatoos
Megalaimidae Asian barbets
Lybiidae African barbets
Capitonidae (v2.6) New World barbets
Semnornithidae (v2.6) Prong-billed barbets

Recognition  of the Sagittariidae, Pandionidae, Pluvianellidae, Nestoridae, and Cacatuidae  is consistent with other classifications.

The  Egyptian Plover is assigned to a monotypic family (Pluvianidae) because it is  not a member of the Glareolidae as previously defined, but instead   constitutes a separate lineage that is the outgroup to plover complex including  stilts and ibisbill etc (Baker et al. 2007, TOL).

The  phylogeny of world barbets and toucans distinguishes the African barbets, Asian  barbets, and New World barbets (and toucans) as separate and equivalent evolutionary  groups. The Asian barbets are a monophyletic lineage that is sister/outgroup to  the rest of the world’s barbets and toucans. In turn, the African barbets are  sister to the New World barbets. We initially included all New World barbets in a single  family (Ramphastidae) that was given equivalent status to the two families of  Old World barbets. As of v2.6, we recognize the Capitonidae and Semnornithidae following  SACC.Not  included in the IOC list (2.0) are 8 other families that are recognized in some  classifications, as follows:

Oceanitidae:  The two subfamilies of “storm petrels” are  not sister taxa (Nunn and Stanley 1996, TOL) and may merit recognition as  separate families (see Christidis and Boles 2008). Initial DNA analyses  indicate that the Hydrobatidae is basal to the other members of the  Procellariiformes, while the Oceanitidae separated from the Procellariidae at a  later stage in the evolution of the tube-nosed seabirds. We propose to recognize  the Oceanitidae when this phylogeny is confirmed.

Rynchopidae:  The current phylogeny of the members of the  Laridae doesn’t support recognition of the skimmers as a separate family (Baker  et al 2007; TOL).  The genus Rhynchops is paraphyletic in relation to  three lineages of terns that occupy different positions in this phylogeny

Batrachostomidae:  The latest phylogeny of frogmouths separates Rigidipenna inexpectata from the genus Podargus (Cleere et al. 2007).  Recognition of the Asian frogmouths (Batrachostomus) as a separate family  (Christidis and Boles 2008) would require treating Rigidipenna as a monotypic family.  We prefer to retain the Podargidae as a  monophyletic taxon that includes the three genera.

Eurystopodidae: The eared-nightjars  (Eurystopodus) are sister to rest of  the Caprimulgidae and are treated as a separate family in some classifications  (Sibley and Monroe 1990; Christidis and Boles 2008) but they are not equal in  rank to Podargidae.

Cerylidae and  Dacelonidae:  The kingfishers of the world include three reciprocally monophyletic groups  (Alcedininae, Cerylininae and Daceloninae) which are sometimes treated as  separate families (Sibley and Monroe 1990; Christidis and Boles 2008).  These three clades, however, are not at the  same rank as the other families in the Coraciiformes.

Suboscine  families

The Eurylaimidae is expanded, tentatively, to  include both the asities of Madagascar (formerly Philepittidae) and Sapayoa of the New World (Irestedt et  al. 2006; Moyle 2006a).  Both the NACC  and SACC treat Sapayoa as a member of  the Eurylaimidae.  But we retain the  Pittidae as sister to the Eurylaimidae (see Hackett et al. 2008).   Some colleagues advocate including all of  them in a single family that embraces this spectacular radiation of colorful  Old World suboscines. An alternative classification would be to recognize 4  separate families of “broadbills” – Philepittidae, Sapayoaidae, Eurylaimidae  and Calyptomenidae (Calyptomena and Smithornis) as well as the Pittidae.  The exact, but currently uncertain position  of Sapayoa relative to pittas versus  broadbills will guide future revisions of this classification.

The  IOC list (2.0) sequence of New World suboscine families follows that of the  SACC (2008), with four additional families in bold font (below). Note that Sharpbill is transferred provisionally to the Tityridae. Genetic data place the Sharpbill in the Tityridae (Ohlson et al. 2008, Tello et al 2009); SACC may retain as a separate family Oxyruncidae along with Myiobius, Terenotriccus, Onychorhynchus ; Tree of Life does not (Harshman 2009).

The relationships of Swallow-tailed Cotinga remain open. Piprites, however, are basal tyrannids, as is Kinglet Calyptura, which forms a clade with Platyrinchus and Neopipo (Ohlson et al, MS/Poster at IOC 2010).

Furnariidae Ovenbirds, woodcreepers
Thamnophilidae Antbirds
Formicariidae Antthrushes
Grallariidae Antpittas
Conopophagidae Gnateaters
Rhinocryptidae Tapaculos
Melanoparaeiidae Crescentchests
Tyrannidae Tyrant flycatchers
Oxyruncidae (to Tityridae v2.3) Sharpbill
Cotingidae Cotingas
Pipridae Manakins
Tityridae Tityras, becards
Incertae sedis Phibalura, Calyptura (see above)
Oscine  families

The  21 added families of oscine passerines are:

Paramythiidae Painted Berrypeckers
Notiomystidae Stitchbird
Tephrodornithidae Woodshrikes
Prionopidae Helmet Shrikes
Psophodidae Whipbirds, quail-thrushes
Hypocoliidae Hypocolius
Ptilogonatidae Silky-flycatchers
Hylocitreidae Hylocitrea; previously Yellow-flanked Whistler
Mohoidae Oos
Stenostiridae Fairy warblers
Panuridae Bearded Reedling
Nicatoridae Nicators
Cettiidae Cettia warblers and allies
Phylloscopidae Leaf warblers and allies
Acrocephalidae Reed warblers and allies
Megaluridae Grassbirds and allies
Donacobiidae Donacobius
Bernieridae Malagasy warblers
Hyliotidae Hyliotas
Buphagidae Oxpeckers
Calcariidae Longspurs and snow buntings

Phylogenetic  revisions of the oscine passerines are arguably the most extensive and complex  of those underway in ornithology. The ongoing revelations about waxwings and  their allies are one case in point.  Several  (oddball) species in monotypic families are known as allies of the waxwings and  silky-flycatchers, e.g. palmchat (Dulidae) of Hispaniola, Hypocolius  (Hypocoliidae) of the Middle East. Adding to them is the revelation that the  Oos (Moho) of the Hawaiian Islands  are bombycillids, not honeyeaters (Meliphagidae) as traditionally believed  (Fleischer et al 2008). And  – the Yellow-flanked Whistler (Hylocitrea) of Sulawesi is yet another surprising  relative of the waxwings (Spellman et al. 2008).

Further,  the Rail-babbler (Eupetes) of  Southeast Asia is not related to the Papuan whip-birds and quail-thrushes  (Psophodidae). Instead it is related to the rockfowl (Picathartes) and rockjumpers (Chaetops)  of Africa (Jønsson  et al. 2007) . Consequently we restrict the family Eupetidae to this species.  Linking  Africa and southeast Asia is the  network of shrike allies that include bushshrikes (Malaconotidae),  helmetshrikes (Prionopidae), vangas (Vangidae), woodshrikes and allies (Tephrodornithdae),  Bristlehead (Pityriasidae), and their outgroup relatives, the ioras (Aegithinidae)  (Moyle et al 2006).

The  shrike-babblers (Pteruthius) and  White-bellied Yuhina (Erpornis) of  southeast Asia are relatives of the vireos, not babblers (Reddy and Cracraft  2007, Reddy 2008). And conversely, the Black-capped Donacobius of South America  is neither a mockingbird (Mimidae) nor a wren (Troglodytidae).  Adding to the list of New World representatives  of Old World families, Donacobius is  a New World representative of the sylvioid grassbirds (Megaluridae) or perhaps  the Malagasy warblers (Bernieridae). The IOC list (2.0) incorporates all such  revelations known to us on December 31, 2008. Other revisions include the resorting  of the Old World Warblers into five families additional to the Cisticolidae,  namely the Cettidae, Phylloscopidae, Megaluridae, Acrocephalidae, Bernieridae following  Cibois et al (2001, Alström et al (2006), Jøhansson et al (2006), Ryan et al (2006).

More  is to come.  We have not yet addressed the  revision of the babblers (Timaliidae) that is underway including integration  of  Sylvia warblers, which are babblers, of white-eyes (Zosteropidae), which are probably  sister to Yuhina babblers, and other  lineage revisions (see Cibois 2003, Gelang et al. 2009). The resorting of the taxonomic   boundaries of New World buntings,  tanagers, warbler, finches, and grosbeaks also will be addressed in a future  update.