Friday, July 07, 2006

New North American Species

The AOU has announced a series of changes in their 47th Supplement to the Checklist of North American Birds. The biggest news for North American birders is the split of Blue Grouse into Dusky Grouse and Sooty Grouse. The two species occur in separate geographic ranges, with the former in the interior and the latter on the coast. The Sibley Guide to Birds depicts both forms, so separating the two will not require a new field guide.

Here are the new species accounts for Dusky Grouse and Sooty Grouse from the Supplement:

Dendragapus obscurus (Say). Dusky Grouse.

The citation remains as it is. Habitat is as for the obscurus group. Distribution is as for obscurus group with the deletion of “from southeastern Alaska (except coastal areas),” and comma following Yukon. Change Notes to: Previously included D. fuliginosus and called Blue Grouse, but now separated on the basis of genetic evidence (Barrowclough et al. 2004) and differences in voice (hooting), behavior, and plumage (Brooks 1929). Barrowclough et al. (2004) also found a lesser genetic difference between northern and southern populations of D. obscurus that does not correspond to currently recognized subspecific boundaries....

Dendragapus fuliginosus (Ridgway). Sooty Grouse.

Canace obscura var. fuligniosa [sic] Ridgeway [sic], 1873, Forest and Stream 1(19):289. (Cascade Mountains, at foot of Mount Hood, Oregon, and Chiloweyuck Depot, Washington = beneath Mount Hood, Hood River County, Oregon.) See Banks and Browning (1979) for citation and Deignan (1961) and Browning (1979) for type locality.

Habitat and Distribution as for fuliginosus group in AOU (1998) account for D. obscurus.

Notes.—Formerly merged with D. obscurus as Blue Grouse, but separated on the basis of genetic evidence (Barrowclough et al. 2004) and differences in voice (hooting), behavior, and plumage (Brooks 1929).
Two other species added because of splits were the Cape Verde Shearwater (split from Cory's Shearwater) and Barbados Bullfinch (split from Lesser Antillean Bullfinch). The Black-bellied Storm-petrel has been added to the checklist due to a sighting off the North Carolina coast.

Other changes on the list mostly concern the ordering and arrangement of family groupings. The tern genus Sterna has been split into five genera: Onychoprion, Sternula, Gelochelidon, Hydroprogne, Thalasseus, and Sterna. Another change for the larids is that Skuas and Jaegers have been given their own family, Stercorariidae, separate from Laridae (Gulls). Among shorebirds, sandpipers in the Catoptrophorus and Heteroscelus genera have been merged into Tringa.

The changes bring the checklist for the AOU area to 2,041 species. Note that unlike the ABA area, the AOU area covers all of North America, from the North Pole to the border of Panama and Colombia, and also includes Hawaii. Presumably many of these changes will be reflected in the next version of the ABA checklist. Read the rest of the Supplement for further details on the changes.

Link via xenospiza.

The study that led to the split of Sooty and Dusky Grouse is here. (Link via Grrlscientist.)