Habitat: Moist deciduous or coniferous forests and areas near running water with tall trees are favored by the western flycatcher (Grinnell and Miller 1944).
Nest: Western flycatchers sometimes nest in cavities, but use a variety of nest sites. Davis et al. (1963) found four nests in natural cavities in willows and oaks, and six behind flaps of bark in sycamores and willows. Nests are often reported in natural rock crevices, on tree limbs and crotches, and on ledges of buildings (Bent 1942, Davis et al. 1963, Beaver 1967).
Food: Almost all of the food of the western flycatcher is insects captured on the wing. An examination of 23 stomachs showed 31 percent flies, 25 percent beetles, 23 percent lepidopterans (including pupae and adults of spruce budworms), and 17 percent hymenopterans (Beaver 1967).
Violet-green swallow
Tachycineta thalassina
L 4¾″
Habitat: Ponderosa pine affords the favorite habitat for violet-green swallows (Bailey and Niedrach 1965), but they are also found in aspen-willow and spruce-aspen forests. They prefer open or broken woods or the edges of dense forests.
Nest: Violet-green swallows nest in holes, cavities, and crevices in a variety of situations. Where birds are abundant, the demand for nest sites is sometimes greater than the supply, and practically any available cavity may be used. These swallows have been reported to use old nests of cliff swallows and even burrows of bank swallow (Bent 1942). Winternitz (1973) reported violet-greens using old woodpecker holes in live aspen as nesting sites, but in Arizona, we found them nesting primarily in old woodpecker holes in ponderosa pine snags. We found one in the dead top of an aspen, 5 in dead tops of ponderosa pine, and 26 in ponderosa pine snags. Nest heights ranged from 16 to 80 feet and averaged 43 feet.
Food: Apparently, the diet of this species is exclusively insects taken on the wing. It includes leafhoppers, leaf bugs, flies, flying ants, and some wasps, bees, and beetles (Bent 1942). In Colorado, Baldwin (pers. comm.[7]) found that insects made up 99 percent of the stomach contents of six violet-green swallows. Flies were the most abundant insect found. Scolytid beetles, seed and leaf bugs, miscellaneous insects, and a few spiders were also found.