The Fifty-first Supplement to The AOU Check-list

It’s that season, and the new Supplement to the AOU Check-list (still so quaintly spelled a century and a quarter after the first edition!) appeared at BioOne yesterday.

The news of a few species “splits” affecting birders in the US and Canada was not unexpected–the only thing surprising, and perhaps a little disappointing to a resolute non-scientist, was that there weren’t more. In any event, we now officially 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 remarkably 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 at the moment, though the copy of the Supplement I printed out today calls it, logically and straightforwardly, “American Scoter.”

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 vermies 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, so it’s nice to see them sharing a taxonomic drawer. I just wish that we could change their English names, too, to echo the genus name: wouldn’t it be nice to go out and see some Orange-crowned Mountain-Chats? And just imagine what high school football teams in Tennessee could do with it.

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.

I tremble to report it, but it’s official now: Aimophila, that wonderful ragbag genus of wonderful ragbag sparrows, has been dismantled. Here in Arizona, 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. (No action on the possible split of Sage into Interior Sage and Bell’s Sage Sparrows.)

These changes, of course, I take personal: my favorite bird in the world, Rufous-winged Sparrow, can no longer serve as the eponym for this b-log or my drowsy little guide service. What shall I do? Kenn suggested renaming it “Peucaea Perambulations,” but I think maybe I’ll just let people think that I can’t identify Rufous-crowned Sparrow and leave it at that.

The revisions don’t stop at the level of genus, either. 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: hurray for Donacobius, sometimes a wren, sometimes a thrasher, now confident enough to simply be itself.

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; I doubt that this particular innovation will last–higher categories generally want to be more densely populated–but that’s the solution of the moment. 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 and 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 (that phrase will take some getting used to!), the Phaethontiformes (tropicbirds), and the Suliformes (frigatebirds, boobies, and cormorants). When I was a boy, back before they’d invented DNA and chemistry and all that, we learned that orders were defined by foot characters: we’ve come a long ways!

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.