Empidonax occidentalis
adult
From Alamy: Glenn Bartley/All Canada Photos/Alamy Stock Photo: Cordilleran Flycatcher.
This species is almost identical to the Pacific-slope Flycatcher, and silent birds—particularly on migration—can be impossible to identify with certainty. The calls and breeding range offer the best clues for separation. The sexes are similar. Adults have olive-brown upperparts (subtly browner than Pacific-slope) and pale underparts, palest on the throat and belly. The eye is accentuated by a white eyering that broadens behind it, and the bill is marginally longer than that of Pacific-slope. The wings are dark, with pale fringes to the inner flight feathers and two dull white wingbars. Juveniles are similar to adults but the wing feather fringes and wingbars are buff.
The Cordilleran Flycatcher is present as a breeding species mainly from May to August; its interior upland breeding range does not overlap that of the Pacific-slope Flycatcher. It spends the rest of the year in Central America. The species adopts an upright posture when perched.
adult
FACT FILE
LENGTH 5.5 in (14 cm)
FOOD Insects and other invertebrates
HABITAT Conifer forests in the Rocky Mountains
STATUS Locally common summer visitor
VOICE Song typically comprises a thin tsee, a chirping see-oo, and a sharp pik. Call is a thin, whistled, disyllabic tsee-seet
