Bird of the Month: Mountain Chickadee
By Andy McCormick
PC: Justin Barton / Great Backyard Bird Count (Mountain Chickadee)
Scientific Name: Poecile gambeli
Length 5.25 in
Wingspan 8.5 in
Weight 0.39 oz
AOU Band code MOCH
A white eye stripe on the Mountain Chickadee is unique among chickadees.
The white supercilium is a prominent field mark that separates the Mountain Chickadee from all other chickadees. This is probably best seen in spring when the feathers are fresh. The white is only the tip of otherwise black feathers and when worn later in the year, the white stripe will be fainter and more difficult to see (Alderfer). Consequently, at times the Mountain can be confused with the Black-capped Chickadee, its closest relative.
However, the difference in the wing feathers provides another good field mark. The edges of the wing feathers are, “pale gray and inconspicuous in the Mountain and prominently white in the Black-capped” (Alderfer). The Mountain also has grayer underparts than the Black-capped (Dunne).
Mountain resident
The Mountain Chickadees is a typical energetic tit that specializes in high altitude living. It usually nests between 8,000 and 10,000 feet (Bell and Gregory). Once it establishes a territory it will remain a resident bird of montane regions and does not migrate. Most Mountain Chickadees will stay in the same area for their entire life.
At times the range of Mountain Chickadees will overlap the ranges of the Black-capped and Chestnut-backed Chickadees. When this occurs the species will generally stay separated. Mountain Chickadees will stay in conifers, leaving the deciduous trees to the Black-capped. When in contact with Chestnut-backed Chickadees, Mountain Chickadees will concentrate on pines, while the Chestnut-backs favor Douglas firs (Dunne).
Mutual Support within Limits
Mountain Chickadees will join in flocks and forage together in winter in order to cache seeds. However, a strict hierarchy by age and sex is observed in the group. Males are dominant over mates, and within sex, older birds are dominate over younger birds. When observed at a feeder, subordinate chickadees will wait until the dominate bird leaves before feeding. In years of low seed production, it is more likely that younger birds will be the ones to move to lower altitude in search of seeds (McCallum, et al).
The Mountain Chickadee is a cavity nester which usually prefers a hole in a tree. The nest is lined with strips of bark, moss, hair, or feathers. Usually 7-9 white eggs dotted with reddish brown are deposited. Incubation, primarily by the female, lasts about 14 days, and first flight takes place in about three more weeks. Parents will continue to feed young after that (Kaufman). During the nesting period females may become more dominant in the flock.
Named for a Young Naturalist
The Mountain Chickadee shares the genus Poecile, from the Greek, poikilos, pied or dappled. Pied refers to the black and white colors. The species name gambeli was given by Thomas Nuttall to honor William Gambel (1823-1849), (Holloway). Gambel was a young naturalist who began studies with Nuttall at age 15. He died at age 26 of Typhoid Fever after being caught in an early snowstorm while crossing the Rocky Mountains in 1849 (Mearns and Mearns). He is credited with discovering the Mountain Chickadee just west of Santa Fe, NM.
Breeding bird surveys show some long-term decline in population numbers, but causes are not known (Alderfer). Mountain Chickadees will readily use next boxes and in some cases prefer them to other nesting sites (McCallum, et al).