MacGillivray's Warbler (Geothlypis tolmiei) [XC378420]
by Skip Russell from Bush Arm, Kinbasket Lake, Columbia-Shuswap, British Columbia, United States (song)
MacGillivray's Warbler (Geothlypis tolmiei) [XC753182]
by Sunny Tseng from Domano Park, Canada (song)
Subspecies
Genus sometimes subsumed in Geothlypis. Forms a species pair with Mourning Warbler (Geothlypis philadelphia), the two probably constituting a superspecies. Ranges overlap in western Canada (Peace Region of British Columbia). Claimed hybrids from this zone have been considered variants of Mourning Warbler (Geothlypis philadelphia) with white eye-crescents (such variants occur throughout that species' range), but recent analysis combining molecular and morphological data sets confirms numerous hybrid individuals with mixed characters, including 18 of 50 birds genotyped (36%) showing both western and eastern alleles.
Proposed subspecies austinsmithi (described from near Chico, in Montana) treated as a synonym of nominate, and intermedia (described from Okanagan, in southern British Columbia) synonymized with monticola.
The following 2 subspecies are recognised:
tolmiei (Townsend, JK, 1839) - Breeds Pacific coastal region and Cascades from extreme south-eastern Alaska and southern Yukon southern in western USA to central California; migrates to region from Mexico south to Guatemala, in smaller numbers to western Panama.
monticola (Phillips, AR, 1947) - Breeds from south-western Canada (eastern British Columbia and south-western Saskatchewan) southern in Rocky Mts and adjacent areas to Arizona and New Mexico, with isolated population in Black Hills of South Dakota-north-eastern Wyoming; migrates to Mexico and Guatemala.
BirdLife International Species Factsheet