AOU Check-list Proposals

As we begin a new birding year, let’s look ahead to proposals that are awaiting action by the American Ornithologists’ Union “Check-list Committee.” Many of these involve ABA Area birds, most notably a split of the Gray Hawk into two species (only one of them found in the ABA Area).

The AOU Committee on Classification and Nomenclature for North and Middle America received 14 proposals during 2011. Here, I’ll summarize four that relate to ABA Area species, and I’ll refer you to the full list on the AOU website.

One split is recommended, but it wouldn’t mean an addition to the ABA Checklist. It would divide the Gray Hawk into a northern species and a southern species, based on differences in plumages, measurements, and vocalizations, along with parallel differences in mitochondrial DNA. The two taxa are said to be entirely separable based on plumage, even where their ranges approach each another in Costa Rica. The species would be:

• Gray Hawk, our ABA Area bird, which breeds from southern Arizona, New Mexico, and Texas southward through Mexico to northwestern Costa Rica. Its scientific name would be changed to Buteo plagiatus.

• Gray-lined Hawk, resident from Costa Rica (except the northwest) southward through South America. By rules of nomenclature, it would retain the current single species’ scientific name, Buteo nitidus.

Just after the AOU adopted the name Bahama Warbler for the new species formerly classified as a Yellow-throated Warbler subspecies, a proposal is made to change the Bahamian endemic’s name to Pinelands Warbler.

The recommendation has a conservation thrust, pointing out that the Bahamian bird is restricted to forests of Caribbean pine—a habitat severely threatened by logging and development. The Bahamas National Trust is campaigning to save what remains, and the Trust believes the name Pinelands Warbler could make the species a “flagship” for the campaign to conserve forests on Abaco and Grand Bahama.

Another proposal would reorganize classification of 16 wren species in the large genus Thryothorus by separating all but one of them into three new genera. Only the Carolina Wren would remain in the genus because recent molecular studies indicate that it is distantly related to other species currently in the genus.

This recommendation would affect the ABA Area list only by changing the Sinaloa Wren’s scientific name from Thryothorus sinaloa to Thryophilus sinaloa.

Following a number of recent reclassifications among sparrow genera, the family Emberizidae could get another reshuffling—although a relatively limited one this time. Sparrow specialist James D. Rising suggests that the Black-throated Sparrow and the Sage Sparrow do not belong in the same genus, Amphispiza, because genetic studies have shown that they are distantly related.

He recommends moving the Sage Sparrow into a new genus of its own, Artemisospiza—a name combining the Latin generic name for sage (Artemisia) with the Greek word for finch, spiza. This move would leave only the Black-throated Sparrow and the Five-striped Sparrow in the genus Amphispiza.