Pacific-slope Flycatcher
(Empidonax difficilis)


Picture of bird
© 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.


Main designations for the species
DesignationStatusDateSubspecies, population
IUCN (Global)Least concern2018 
Wild Species (Canada)Secure2015 
Bird Conservation Region StrategyPriority Species2013 

Population status

Geographic area or populationPopulation change relative to ~1970ReliabilityStatus in relation to goal
CanadaModerate IncreaseMediumAt an Acceptable Level

Population estimate

Geographic area or populationPopulation estimate
Canada1,000,000 - 5,000,000 adults

Distribution maps


Migration strategy, occurrence

Long-distance migrant

Responsibility for conservation

Geographic areaResponsibility based on % of global population

General nesting period in Canada

Nesting period starts between early June and mid-June and ends between early August and mid-August, depending on the region. Before or after this period, the probability of an active nest is lower. These estimates cover the periods of the Cordilleran Flycatcher and the Pacific-slope Flycatcher.

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.

BCRs, marine biogeographic units, and sub-regions in which the species is listed as a priority
RegionSub-region and priority type
Northern Pacific RainforestNorthern Pacific Rainforest, sub-region and priority type: Pacific and Yukon -- Stewardship