The fifty-first Supplement to the AOU Check-list (still so quaintly spelled a century and a quarter after the first edition!) has been published.
In the US and Canada, we now have two whip-poor-wills, Mexican Whip-poor-will and Eastern Whip-poor-will, and the old “winter” wren is now recognized as three species, two of which–Pacific Wren and the poorly named Winter Wren sensu novo strictoque–occur in North America. “Our” black scoter is split from the Old World species and renamed Melanitta americana, vindicating good old Swainson a hundred seventy-five years after he described it; its English name is apparently uncertain, but will probably be Black Scoter in opposition to the Old World’s Common Scoter (the version of the Supplement at BioOne calls it American Scoter, but that is rumored to be a typographic error).
While species determinations speak only to identity, genera are all about relationships, and this Supplement is full of new views about what belongs with what. Canyon, California, and Abert’s Towhees are moved over to Melozone, which they’ll be sharing with the tropical ground-sparrows; only the three rufous-sided and Green-tailed Towhees remain in the cheerful-sounding genus Pipilo.
There are some significant innovations in the warblers, too, both Old World and New. Here in North America, Vermivora is greatly diminished, now including, if I count right, only Blue-winged, Golden-winged, and the ghost of Bachman’s Warblers. The handsome old genus Oreothlypis is resurrected to contain all the other erstwhile Vermivora and two tropical “parulas,” Flame-throated and Crescent-chested Warblers; visually and intuitively, those latter two have always been thought of as intermediate between the parulas and the old-style Vermivora.
Another pair of warblers, the waterthrushes, have now got their own genus, Parkesia, bearing the name of one of the last century’s greatest museum men and warbler experts. Ovenbird stays behind to brandish its tail in Seiurus, no doubt to the posthumous frustration of Eliot Coues, who argued long and hard that it should by rights have been spelled Siurus.
It’s official now: Aimophila, that wonderful ragbag genus of wonderful ragbag sparrows, has been dismantled. In the US, only Rufous-crowned Sparrow is still an Aimophila, our others moved into the revived genus Peucaea. Five-striped Sparrow, always an uncomfortable nomenclatural fit, has gone back to Amphispiza, joining once again the visually similar Sage and Black-throated Sparrows.
The revisions don’t stop at the level of genus. There are eleven new families recognized, including the re-elevation of Osprey and the gnatcatchers to family status; the longspurs and white buntings also get their own family, Calcariidae (and McCown’s Longspur goes its own way generically once again).
The Old World “warblers,” a miscellaneous bunch if ever there was one, are broken into many families: Cettiidae includes the bush warblers, Phylloscopidae the leaf warblers, Sylviidae the round-headed chattering warblers (now including Wrentit), and Acrocephalidae the reed warblers. Those new Eurasian families are followed in sequence by an American one, Donacobiidae, including the Donacobius.
Most far-reaching of all is the re-organization of a couple of non-passerine orders. Sunbittern and Kagu, two of the most extravagantly plumed birds anywhere, now get their own order, Eurypygiformes. The falcons and the other diurnal raptors are split into two orders, falcons and caracaras keeping hold of the old Falconiformes and the rest inserted into a new Accipitriformes.
And then there are the storks and pelicans. Ciconiiformes relinquishes everything but the storks themselves; the herons and ibises are now part of the order Pelecaniformes, where they sit alongside the pelicans to form the suborders Ardeae (herons and bitterns) and Threskiornithes (ibises and spoonbills).
The committee giveth and the committee taketh away, and the old totipalmate swimmers are now split up into three orders: the pelicans and herons in Pelecaniformes, the Phaethontiformes (tropicbirds), and the Suliformes (frigatebirds, boobies, and cormorants).
And changes will continue. The committee rejected proposals to split the scrub-jays and the curve-billed thrashers, but watch the “pending” section of the committee’s web page for new proposals–and look forward to next July when the next Supplement will be published.
Birders interested in the taxonomy of South American birds will also want to keep up with the deliberations of the South American Checklist Committee.