Mountain chickadees are similar-looking to the black-capped chickadee, but the mountain chickadee has a longer bill. A distinguishing characteristic is its white eyebrow. This may be hard to see when the bird is in worn plumage, however. The top of the head is sooty black as are the lores and eye stripe. Males, females and juveniles all look alike with gray flanks and undertail feathers. Adult mountain chickadees measure between five and six inches from head to tail. Their call is a chick-a-dee-a-dee-a-dee or it can be a whistle of fee-bee-bay or fee-bee, fee-bee with the notes coming down scale, such as in the song of "Three Blind Mice." Mountain chickadees are also referred to as short-tailed chickadee, Bailey’s chickadee, Grinnell’s chickadee and Inyo chickadee.
Range: Mountain chickadees can be found at higher elevations in the western United States and Canada. As the name implies, the mountain chickadee is found in mountainous regions from 6,500 to 12,000 feet above sea level wherever conifer trees are found. Mountain chickadees are found in all of Colorado’s mountain ranges with highest concentrations in the San Juan Mountains. Because they avoid lower valleys, they are absent from treeless parts of North Park and the San Luis Valley, but do nest in the woodlands scattered across Middle and South Parks.
Habitat: They nest in coniferous and mixed coniferous-deciduous forests. They are residential species, which means they do not migrate; however, they may move to lower elevations during the winter. Indications are that adults tend to stay close to breeding areas but first-year birds are more apt to move lower in winter.
Diet: Their diet consists mainly of insects and other invertebrates, berries and seeds. In the winter when food is hard to find or in short supply, they often visit bird feeders.
Reproduction: They prefer to nest in cavities, snags, abandoned woodpecker holes, nest boxes, under rocks or other available sites. They occasionally excavate their own site if one is not readily available. The female will lay one white, semi-glossy egg per day with the average clutch size ranging from five to nine eggs. Incubation lasts fourteen days after the next-to-last egg is laid. The female will not leave her nest easily. She will try to ward off predators with a hissing sound. As the female incubates the eggs, the male mountain chickadee will bring her food. The male continues to bring food back to the nest after the young hatch. The nestlings leave after 19 to 21 days. Mountain chickadees will cross breed with black-capped chickadees.
For more information, see the Natural Diversity Information Source species profile.