Species: Empidonax occidentalis

Cordilleran Flycatcher

Species

Birds

Encyclopedia of Puget Sound

Classification

Kingdom

Animalia

Phylum

Craniata

Class

Aves

Order

Passeriformes

Family

Tyrannidae

Genus

Empidonax

NatureServe

Source:
ELEMENT_GLOBAL.2.100103

Classification

Other Global Common Names

Mosquero Barranqueño - Moucherolle des ravins

Informal Taxonomy

Animals, Vertebrates - Birds - Perching Birds

Formal Taxonomy

Animalia - Craniata - Aves - Passeriformes - Tyrannidae - Empidonax - Formerly considered conspecific with E. DIFFICILIS (AOU 1989, 1998). Referred to as E. D. HELLMAYRI by Johnson and Martin (1988). Johnson and Marten (1988) examined variation in the E. DIFFICILIS group and concluded that E. DIFFICILIS and E. OCCIDENTALIS are distinct species. Phillips (1994) argued that existing information does not justify the recognition of E. OCCIDENTALIS and E. DIFFICILIS as distinct species. Johnson (1994) provided additional analyses indicating that E. DIFFICILIS and E. OCCIDENTALIS warrant separate-species status. Constitutes a superspecies with E. DIFFICILIS and E. FLAVESCENS (AOU 1998).

Ecology and Life History

Short General Description

A small bird (flycatcher).

Migration

false - false - true - Most arrive in central Colorado late in May (some as early as April), depart by late September; present in Montana usually late May-August (Niedrach and Rockwell 1939, Johnsgard 1986).

Non-migrant

false

Locally Migrant

false

Food Comments

Feeds on insects, also berries and occasionally seeds (Ehrlich et al. 1988). Most often hawks aerial insects, but also gleans insects from foliage and off the ground (USDA Forest Service 1994). In a Colorado study, Lepidoptera made up 61 percent of diet by dry weight, also consumed Coleoptera, Diptera, and Hymenoptera (Beaver and Baldwin 1975).

Reproduction Comments

Egg dates: June-July in Colorado, July in Montana (Johnsgard 1986). Incubation 14-15 days, by female along; young fledge after 14-18 days, fed by parents another 10-11 days (Baicich and Harrison 1997).

Ecology Comments

Rich (1999) found significant correlations between the relative abundance of cordilleran flycatcher and the abundance of warbling vireo (VIREO GILVUS), red-naped sapsucker (SPHYRAPICUS NUCHALIS), and Lincoln's sparrow (MELOSPIZA LINCOLNII), which tend to occur in similar habitats. There were weaker but significant associations with blue grosbeak (GUIRACA CAERULEA), house wren (TROGLODYTES AEDON), Bell's vireo (VIREO BELLII), and Lucy's warbler (VERMIVORA LUCIAE).

Conservation Status

NatureServe Global Status Rank

Global Status Last Reviewed

1996-12-02

Global Status Last Changed

1996-12-02

Other Status

LC - Least concern

Distribution

Conservation Status Map

Global Range

BREEDING: southeastern Washington, southwestern Alberta, northern Idaho, western Montana, Wyoming, and western South Dakota south (generally east of Cascades and Sierra Nevada) to northern California, Nevada, and central and southeastern Arizona, and in Mexican highlands to Oaxaca (west of Isthmus of Tehuantepec), Puebla, and west-central Veracruz, and east to western Nebraska (rarely), central Colorado, central New Mexico, and western Texas (AOU 1989). Centers of abundance occur in Arizona, New Mexico, Colorado, central Utah, the Black Hills region of South Dakota, and northern Idaho (Sauer et al. 1997). NON-BREEDING: southern Baja California, and northern Mexico (casually to central California and southern Arizona) south through breeding range, occurring also in lowland areas south to Isthmus of Tehuantepec; reports from Chiapas, Guatemala, and Honduras are based on E. FLAVESCENS (AOU 1989). Casual in migration in Tres Marias Islands (off Nayarit), eastern New Mexico, and southwestern Kansas (AOU 1989).

ELEMENT_GLOBAL.2.100103