Cordilleran Flycatcher

The Western Flycatcher, known scientifically as Empidonax difficilis, is a diminutive bird that belongs to the Tyrannidae family. This insectivorous avian graces the forests and mountain ranges of western North America with its presence. Adults are adorned with olive-gray upperparts, which darken across the wings and tail, and their underparts exhibit a yellowish hue. A distinctive teardrop-shaped white eye ring and white wing bars are notable, along with a modestly sized bill and a short tail.

Identification Tips

Distinguishing the Western Flycatcher from its congeners can be quite the challenge, as many species within the Empidonax genus bear a striking resemblance to one another. The most reliable methods for identification include listening to its unique vocalizations, observing its preferred breeding habitats, and understanding its geographical range. A recent discovery through DNA testing has revealed that the extent of buffy edging on the secondaries is a reliable field mark to differentiate this species from the Yellow-bellied Flycatcher.

Habitat

The Western Flycatcher is a denizen of both coniferous and deciduous woodlands. Its habitat selection is diverse, ranging from mixed woods and Douglas fir forests to redwood and pine-oak forests, as well as riparian woodlands. These birds are often found breeding in proximity to running water, constructing their cup nests low in the horizontal branches of trees.

Distribution

Breeding from the Rocky Mountains to the Pacific Coast forests, the Western Flycatcher's range extends from California to Alaska and reaches down to central Mexico. When winter descends, the northern populations embark on a migration to Mexico, where they find solace until the return of warmer seasons.

Behaviour

The Western Flycatcher is a master of the aerial hunt, often perched patiently before darting out to capture flying insects in a behavior known as "hawking." They are also adept at "gleaning," plucking insects from foliage while hovering. These birds play a pivotal role in controlling insect populations, particularly those of mosquitoes.

Song & Calls

The Western Flycatcher's vocal repertoire includes a series of notes often transcribed as "pseet," "ptsick," and "seet," which are typically delivered in rapid succession. The male's position call is a loud and distinctive "pit pete" or "tse-seet," although variations such as a "rising tsweep" or a "slurred tseeweep" have been noted.

Breeding

During the breeding season, females lay two to five eggs in their carefully constructed cup nests. These nests are strategically placed on a fork in a tree, usually at a low elevation on a horizontal branch.

Similar Species

The Western Flycatcher was once considered a single species with the Cordilleran Flycatcher, but despite their visual similarities, they were split based on differences in breeding habitats and vocalizations. However, due to extensive hybridization and a lack of consistent differences, they were re-lumped as one species by ornithological authorities.

Diet and Feeding

The diet of the Western Flycatcher consists primarily of flying insects, which they catch mid-flight or glean from foliage. They also consume caterpillars and spiders, contributing to the balance of these populations in their ecosystems.

Conservation Status

The IUCN Red List classifies the Western Flycatcher as Least Concern, indicating that, currently, there are no immediate threats to its population numbers that would warrant a higher level of concern.