Olive-sided Flycatcher (Contopus borealis)
Associated Species: Other species that may use habitat in a similar way and/or respond similarly
to threats, management, and conservation activities include Three-toed Woodpecker and
Distribution: Olive-sided Flycatchers' distribution follows the boreal forest, which describes a
broad band from central Alaska south and east across Canada; the populations stretch south into
southern California and through the Rockies into southern New Mexico. Olive-sided Flycatchers
breed in suitable habitat throughout Physiographic Area 62. They winter in southern Mexico,
Central and South America.
Habitat Requirements: Olive-sided Flycatchers reside in mature spruce-fir and mixed-conifer
forests. They are closely associated with burned areas, where they take advantage of the open
forest structure for aerial pursuit of insects. They hunt from snags or trees that extend above the
canopy, often frequenting steep slopes where tall snags or live trees afford opportunities for
unimpeded aerial sallying.
Ecology: Olive-sided Flycatchers arrive on the breeding grounds in Colorado in May. They
initiate nesting by late May, and most young leave the nest by August. Most of these flycatchers
leave the breeding grounds by early September. Their diet consists exclusively of flying insects,
especially bees and flies.
Management Issues and Conservation Recommendations: Clearcuts may provide a forest
structure similar to that of stand-replacement fires. However, the suitability of clearcuts as habitat
for Olive-sided Flycatchers and other members of the post-fire avian guild has not been assessed.
Fire suppression precludes creation of breeding habitat. Allow stand-replacing fires to burn.
Leave the tallest trees and snags when implementing salvage cuts after fires, insect outbreaks, or
blow-downs; exclude some affected areas entirely from salvage cutting. In timber harvest
prescriptions, include the creation of forest openings with tall trees or snags around the margins.
Status and Reasons for Concern: Although this species is apparently secure in this
physiographic area, it is declining in other parts of its range, indicating sensitivity to habitat
change or other events. In light of natural resource agency fire suppression policies and the
Olive-sided Flycatcher's association with post-fire habitats, the species could be expected to
decline across its range. The Olive-sided Flycatcher is classified as a Sensitive Species in U.S.
Forest Service Region 2. Within Physiographic Area 62, BBS data do not show a statistically
significant annual rate of change between 1966 and 1996 (P = 0.78; n = 35 routes). However,
BBS data for the same period reveal a significant, survey-wide annual rate of decline (-3.9%; P <
0.01; n = 683 routes). Olive-sided Flycatchers were present on an average of 59.92% (SE =
2.35) of the BBS routes run in Physiographic Area 62 in Colorado during 1988-1997, at an
average abundance of 2.74 (SE = 0.13) 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: Altman 1997, Andrews and Righter 1992, Hutto 1995, Kingery 1998.