Cordilleran Flycatcher (Empidonax occidentalis)
Associated Species: Other species that may use habitat in a similar way and/or respond similarly
to threats, management, and conservation activities in coniferous riparian forests include Broad-tailed Hummingbird, Ruby-crowned Kinglet, Golden-crowned Kinglet and Swainson's Thrush. In
deciduous riparian forests, associates include Western Wood-Pewee, Warbling Vireo, Yellow
Warbler, and Song Sparrow.
Distribution: Cordilleran Flycatchers breed throughout the Rocky Mountains, from Oaxaca,
Mexico, north to southeastern Alaska. In Colorado they are uncommon to fairly common
summer residents in the foothills and lower mountains from 1800 to 3000 m (6,000-10,000 ft)
elevation. They winter in Mexico and Central America.
Habitat Requirements: These flycatchers nest in shady coniferous and deciduous forests,
usually near streams or moist ravines. They place their nest in roots of upturned trees and forked
branches; small cavities in rock ledges, dirt banks, trees, and snags; and occasionally in niches in
cabins and other structures.
Ecology: Cordilleran Flycatchers arrive on their breeding grounds in early to mid May. Nest
building occurs from mid May to mid July, with young present from mid June to mid August. Fall
migration begins in mid August.
Management Issues and Conservation Recommendations: As is the case with most species,
the most pressing conservation issue is habitat loss. Timber cutting, livestock grazing, and
recreational developments contribute to this loss. Reduce or eliminate any activities that degrade
the structure and quality of the overstory or understory of riparian systems, i.e., maintain
riparian vegetation with a closed canopy, shrubby understory, snags, and downed trees. Do not
permit timber cutting within 30 m (100 ft) of the riparian area. Tightly control or eliminate
domestic livestock grazing in these areas. Summer grazing should not be permitted. Locate
recreational facilities such as roads, trails, and campgrounds away from riparian areas (Myers
Status and Reasons for Concern: A high proportion (estimated at 11.3%) of these flycatchers'
total population occurs within this physiographic area, indicating that this area has high
responsibility for the conservation of this species. BBS data for Physiographic Area 62 did not
demonstrate a statistically significant trend for the period 1966-1996 (P = 0.57; n = 29 routes).
Cordilleran Flycatchers were present on an average of 53.79% of BBS routes run in
Physiographic Area 62 in Colorado, 1988-1997, at an average abundance of 3.03 (SE = 0.35)
individuals per route. The mean number of routes run each year was 21.1 (SE = 3.06). This
species is monitored by MCB with point transects.
Biological Objective: Maintain or increase the species' distribution and abundance, based upon
results from the BBS and MCB monitoring programs.
Selected References: Andrews and Righter 1992, Beaver and Baldwin 1975, Kingery 1998.