Pacific-slope Flycatcher
(Empidonax difficilis)

Overview

Summary

© Ralph Hocken
For additional photos and vocalizations, visit Dendroica. (Link opens in a new window.)

The Pacific-slope Flycatcher was recognised as a distinct species in 1989 (American Ornithologists' Union 1989) when the "Western Flycatcher" complex was split into Cordilleran and Pacific-slope Flycatchers. Almost all of its Canadian range is within British Columbia. Breeding Bird Survey results suggest that the population has increased by some 70% since the early 1970s. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.

Designations

Population status

Population estimate

Distribution maps

• BirdLife International / NatureServe
• North American Breeding Bird Survey (BBS): Relative Abundance and Breeding Distribution (1970-2016)
• British Columbia Breeding Bird Atlas (2008-2017): Breeding Evidence

Migration strategy, occurrence

Responsibility for conservation

General nesting period in Canada

Conservation and management

Recent speculation that the Pacific-slope Flycatcher may be a "molt-migrant" (Carlisle et al. 2009; i.e., a migration pattern in which birds move from the breeding ground to a temporary location to molt, then continue to migrate to a wintering range) may lend greater importance to migration and stop-over sites. This species may be subject to similar influences and threats facing other aerial insectivores (see, for example, Smith et al. 2015, Nebel et al. 2010).

Bird conservation region strategies

Environment and Climate Change Canada and partners have developed Bird Conservation Region Strategies in each of Canada’s Bird Conservation Regions (BCRs). In these strategies, selected species are identified as priorities for one or more of the following reasons:

• conservation concerns (i.e., species vulnerable due to population size, distribution, population trend, abundance, or threats)
• stewardship responsibilities (i.e., species that typify the regional avifauna or have a large proportion of their range or population in the sub-region)
• management concerns (i.e., species that require ongoing management because of their socio-economic importance as game species, or because of their impacts on other species or habitats)
• other concerns (i.e., species deemed a priority by regional experts for other reasons than those listed above or because they are listed as species at risk or concern at the provincial level)

Select any of the sub-regions below to view the BCR strategy for additional details.

References

• American Ornithologists' Union. 1989. Thirty-seventh supplement to the American Ornithologists' Union check-list of North American birds. Auk 106:532-538. American Ornithologists' Union. 1989. Thirty-seventh supplement to the American Ornithologists' Union check-list of North American birds. Auk 106:532-538. (Link)
• Carlisle, J.D., S.K. Skagen, B.E. Kus, C. van Riper III, K.L. Paxton, and J.F. Kelly. 2009. Landbird migration in the American West: Recent progress and future research directions. Condor 111(2): 211–225.
• Nebel, S., A.M. Mills, J.D. McCracken and P.D. Taylor. 2010. Declines of aerial insectivores in North America follow a geographic gradient. Avian Conservation and Ecology 5(2): 1. Nebel, S., A.M. Mills, J.D. McCracken and P.D. Taylor. 2010. Declines of aerial insectivores in North America follow a geographic gradient. Avian Conservation and Ecology 5(2): 1. (Link)
• Smith, A.C., M-A.R. Hudson, C.M. Downes, and C.M. Francis. 2015. Change points in the population trends of aerial-insectivorous birds in North America: Synchronized in time across species and regions. PLOS ONE 10(7): e0130768. doi: 10.1371/journal.pone.0130768. Smith, A.C., M-A.R. Hudson, C.M. Downes, and C.M. Francis. 2015. Change points in the population trends of aerial-insectivorous birds in North America: Synchronized in time across species and regions. PLOS ONE 10(7): e0130768. doi: 10.1371/journal.pone.0130768. (Link)