The Cordilleran flycatcher (Empidonax occidentalis), with its seasonal territories extending from the U.S.-Canadian border to southern Mexico, is found primarily in the Rocky Mountains. It belongs to the order Passeriformes and the family Tyrannidae (Lowther et al 2016). The preferred habitat for E. occidentalis is mainly deciduous or mixed deciduous-coniferous forests and shady canyons, but while breeding they are found in mountainous regions and they forage in conifers like Douglas Fir and various pines. They tend to inhabit slightly drier and more open areas than the almost identical Pacific-slope flycatcher (E. difficilis), which is found in the coast mountain ranges of the West, rather than in the Rockies (Kaufman 2018).
The adult Cordilleran flycatcher has yellow-olive to olive coloration on its back with a yellow underside, the yellow extending up to the throat under its broad bill (Lowther et al 2016). It has prominent olive and white wing-bars and pale yellow eye rings which form into a teardrop shape. It also typically has four long, olive-brown tail feathers. Both males and females are approximately 5.5-6.7 inches in length, weigh about 0.4-0.5 ounces, and have a wingspan of roughly 8.7 inches. The juveniles look very similar to the adults, but they have distinct buffy wing-bars that transition to white and olive as they mature (All About Birds 2018). This bird is difficult to spot since it is small in size but can be identified by the male’s call, a thin, high-pitched, distinctly two-part tii-seet, which differs somewhat from the upslurred tseeweep of E. difficilis (Sibley 2003).
The Cordilleran flycatcher has a distinctive feeding behavior, as it watches from a perch and then flies out to catch insects in the air or from trees and shrubs. Its diet consists mostly of insects, including wasps, bees, flies, caterpillars, moths, and beetles. The parents deliver the food to the nestlings until they take their first flight, which occurs between 14-18 days. Since the Cordilleran flycatcher is rarely spotted, it is apparently a relatively solitary bird that spends most of its maintenance time alone (Kaufman 2018).
E. occidentalis usually lays three to four white eggs with brown blotches concentrated near the larger end, which are incubated for about 14-15 days. Nest sites are either in a small tree, in a cleft in a vertical streambank, on a stump, or in the upturned roots of a fallen tree. The nests are built by the female and are made up of moss, grass, roots, leaves, and feathers. When the Cordilleran flycatcher migrates, it usually arrives at breeding grounds in May and leaves in September (All About Birds 2018).
Data from the Breeding Bird Survey for E. occidentalis is combined with that for E. difficilis and shows that the estimated population for both species in the United States and Canada is 8.3 million individuals (Lowther et al 2016).
The Cordilleran flycatcher (Empidonax occidentalis) is a small insect-eating bird. It is a small Empidonax flycatcher, with typical length ranging from 13 to 17 cm.
Adults have olive-gray upperparts, darker on the wings and tail, with yellowish underparts; they have a conspicuous teardrop-shaped white eye ring, white wing bars, a small bill and a short tail. Many species of this genus look closely alike. The best ways to distinguish species are by voice, by breeding habitat, and by range. This bird is virtually identical to the Pacific-slope flycatcher. These two species were formerly considered a single species known as western flycatcher. The species were split by the American Ornithologists’ Union in 1989.[2] The Pacific-slope flycatcher is a breeding bird of the Pacific Coast forests and mountain ranges from California to Alaska; the Cordilleran is a breeding bird of the Rocky Mountains. They have different songs and calls.
Cordilleran flycatchers' preferred breeding habitat is pine-oak or coniferous forest, usually near running water. They make a cup nest on a fork in a tree, usually low in a horizontal branch. Females usually lay two to five eggs.
These birds migrate to Mexico for the winter, where the Mexican central-southern birds are resident. The non-resident birds are on the western coast from Jalisco northwards, and then to inland regions, in a corridor strip on the western flank of the Sierra Madre Occidental.
The Cordilleran flycatcher waits on an open perch of a shrub or low branch of a tree and flies out to catch insects in flight (hawking), and also sometimes picks insects from foliage while hovering (gleaning).
The song includes notes represented as pseet, ptsick, seet usually sung rapidly together. The ptsick or ptik note has the first syllable higher-pitched than the second—the only difference from the Pacific-slope flycatcher's song (Sibley 2000). The male's typical position call is a loud and distinctive pit pete or tse-seet, but some give a "rising tsweep" or a "slurred tseeweep, like the calls of Pacific-slope flycatchers (Sibley 2000).
The Cordilleran flycatcher (Empidonax occidentalis) is a small insect-eating bird. It is a small Empidonax flycatcher, with typical length ranging from 13 to 17 cm.
Adults have olive-gray upperparts, darker on the wings and tail, with yellowish underparts; they have a conspicuous teardrop-shaped white eye ring, white wing bars, a small bill and a short tail. Many species of this genus look closely alike. The best ways to distinguish species are by voice, by breeding habitat, and by range. This bird is virtually identical to the Pacific-slope flycatcher. These two species were formerly considered a single species known as western flycatcher. The species were split by the American Ornithologists’ Union in 1989. The Pacific-slope flycatcher is a breeding bird of the Pacific Coast forests and mountain ranges from California to Alaska; the Cordilleran is a breeding bird of the Rocky Mountains. They have different songs and calls.
Cordilleran flycatchers' preferred breeding habitat is pine-oak or coniferous forest, usually near running water. They make a cup nest on a fork in a tree, usually low in a horizontal branch. Females usually lay two to five eggs.
These birds migrate to Mexico for the winter, where the Mexican central-southern birds are resident. The non-resident birds are on the western coast from Jalisco northwards, and then to inland regions, in a corridor strip on the western flank of the Sierra Madre Occidental.
The Cordilleran flycatcher waits on an open perch of a shrub or low branch of a tree and flies out to catch insects in flight (hawking), and also sometimes picks insects from foliage while hovering (gleaning).
The song includes notes represented as pseet, ptsick, seet usually sung rapidly together. The ptsick or ptik note has the first syllable higher-pitched than the second—the only difference from the Pacific-slope flycatcher's song (Sibley 2000). The male's typical position call is a loud and distinctive pit pete or tse-seet, but some give a "rising tsweep" or a "slurred tseeweep, like the calls of Pacific-slope flycatchers (Sibley 2000).
Position note of Cordilleran flycatcher A position note from a Cordilleran flycatcher in the Black Hills of South Dakota Problems playing this file? See media help.
