Mexican Chickadee (Poecile sclateri) [XC34613]
by Andrew Spencer from Barfoot Junction, Cochise Co., Arizona, United States (call)
Mexican Chickadee (Poecile sclateri) [XC587125]
by Isain Contreras Rodr\u00edguez from Parque las maravillas, Ciudad de M\u00e9xico, Mexico (call)
Subspecies
Until recently present genus normally subsumed into a broad Parus, and many authors still prefer that treatment. Genus normally treated as feminine, but no evidence in original description or elsewhere justifies this, so genus is masculine by default. Has been placed in a superspecies with Mountain Chickadee (Poecile gambeli), sometimes including also Willow Tit (Poecile montanus), Carolina Chickadee (Poecile carolinensis) and Black-capped Chickadee (Poecile atricapillus). DNA analysis, however, suggests closer relationship to Boreal Chickadee (Poecile hudsonicus) and Chestnut-backed Chickadee (Poecile rufescens). Further research is required. Geographical variation largely clinal, size decreasing from north to south. Subspecies poorly defined, and intergrade widely. Species possibly better treated as monotypic, as differences among populations slight and perhaps not sufficiently constant to warrant naming of subspecies.
The following 4 subspecies are recognised:
eidos (Peters, JL, 1927) - Extreme southern USA (south-eastern Arizona, south-western New Mexico) and northern Mexico (northern and central Sierra Madre).
sclateri (Kleinschmidt, 1897) - Central Mexico (central and southern Sierra Madre).
BirdLife International Species Factsheet