Food: Insects probably make up a large portion of the diet (Bent 1946). Telford and Herman (1963) collected 10 birds in the Inyo National Forest, where there was an infestation of lodgepole needle miners and found 639 needle miner caterpillars in chickadee stomachs. Baldwin (pers. comm.[8]) examined the contents of 17 stomachs from the Wet Mountains, Colorado, and found that 75 percent of the summer diet was insects. Large numbers of spruce aphids were found, as well as flies, beetles, hymenopterans, and other insects. Vegetable material included seeds, spruce buds, and fruits. In southwestern Montana, during summer, mountain chickadees fed on lepidopteran larvae, especially cone worms and spruce budworms (DeWeese et al.[9][in prep.]), and insects made up about 98 percent of the diet. Gray-headed chickadee _Parus cinctus_ L 4¾″ [Illustration] Habitat: Broken forests or edges of aspen, willow, and spruce are the preferred habitat of the gray-headed chickadee. The range is limited to western Canada and Alaska. Nest: Old woodpecker holes or natural cavities are selected as nest sites. Bent (1946) reported one nest about 6 feet above ground in a spruce snag. Food: No information could be found in the literature on the food habits of the gray-headed chickadee, but the diet is probably similar to that of other chickadees. Boreal chickadee _Parus hudsonicus_ L 4¼″ [Illustration] Habitat: The boreal chickadee is fairly common in northern forests of spruce, fir, aspen, and birch (McLaren 1975). Nest: Natural cavities, old woodpecker holes, or cavities excavated by the chickadees themselves are used for nesting (Bent 1946). McLaren (1975) found 22 nest holes, all in trees or snags with soft heartwood, and believed that softness of the core rather than a preference for a certain tree species is the determining factor in nest site selection. Food: In summer the boreal chickadee consumes caterpillars, moths, beetles, other insects, and insect eggs; birch cones, seeds, and cedar berries are eaten in the fall and winter (Bent 1946). Chestnut-backed chickadee _Parus rufescens_ L 4¼″ [Illustration] Habitat: Coniferous forests of the humid coastal belt from Alaska to central California are the favorite habitat, but this bird is also found in adjacent deciduous woodlands and along streams (Peterson 1961, Grinnell and Miller 1944). Nest: Nests of this species are in abandoned woodpecker holes or in cavities excavated by the bird itself. Nests have been found in pine, oak, and Douglas-fir snags (Bent 1946). Food: The diet is made up of about 65 percent animal and 35 percent vegetable matter. Of the animal material, 25 percent is hemipterans, 18 percent caterpillars, 13 percent wasps, 7 percent spiders, and 2 percent beetles. Seeds and fruit make up the vegetable material (Beal 1907). Tufted titmouse _Parus bicolor_ L 5½″