Thursday, June 16, 2011
Yellow-rumped Warbler Split?: No
. . . American Ornithological Union (AOU) update:
It votes down (in 2011) splitting Yellow-Rumped Warbler into two, three or four species
(Audubon's Yellow-rumped subspecies appears in photo.)
As many of you already know, the Yellow-rumped Warbler currently occurs as four subspecies, according to many researchers: the “Myrtle” group (coronata), and the “Audubon’s” group (auduboni), “Black-fronted” (nigrifrons), and “Goldman’s” (goldmani)
The taxonomy of these Yellow-rumped Warbler subspecies was under consideration for change by a committee in the American Ornithologist Union (AOU).
(NOTE #1: In the N.A. Birds Online account for this species, the following additional subspecies is described in the "Myrtle group": Yellow-rumped Warbler subspecies: D. c. hooveri (McGregor, 1899). This subspecies breeds in central and s.-central Alaska, se. Alaska, Yukon Territory, Mackenzie, and nw. British Columbia; intergrades with auduboni known from Stikine River, AK (Gibson and Kessel 1997). Like nominate coronata, slightly larger, with longer wing (minimum wing length 73.5 mm in females, 75.5 mm in first-year males, and 78.0 mm in adult males); more streaked below (Alternate-plumaged males) or paler brown (females). Characters broadly clinal where range meets that of nominate coronata; for this reason, hooveri not recognized by Hubbard (1970). More recently, hooverimaintained as valid (Godfrey 1986, Gibson and Kessel 1997, R. Dickerman and P. Unitt pers. comment.
NOTE #2: The International Ornithogical Council (IOC) splits the subspecies and recognizes Audubon's and Myrtle as two species)
Now the vote is in from the AOU (from 2011).
No hanging chads here.
The vote was 7–4 against any divisions of the Yellow-rumped complex. The committee members suggested the need for further genetic analysis and determination of the extent of interbreeding in the subspecies’ contact zones where the “Myrtle” group (coronata), and the “Audubon’s” group (auduboni) mix in western Canada. The status of two other subspecies — “Black-fronted” (nigrifrons), and “Goldman’s” (goldmani) remain unchanged.
Black-fronted is a resident in Mexico, and Goldman’s occurs only in southernmost Mexico and Guatemala. Neither of these two subspecies has been observed in the American Birding Association geographical area.