- 5.5–6.7 in
- 7.9–9.1 in
- 0.3–0.4 oz
- Western Flycatcher (in part)
- Moucherolle côtier (French)
- Mosquero californiano (Spanish)
- The population of Pacific-slope Flycatcher breeding on the Channel Islands off southern California may actually be best treated as a distinct species. It is larger than mainland populations, has a longer bill, a paler chest, slightly different vocalizations, and differs genetically.
- The scientific name of the Pacific-slope Flycatcher, difficilis, is appropriate. It means "difficult," and this species is extremely difficult to distinguish from the similar Cordilleran Flycatcher.
Warm, humid lowland coniferous forest, pine-oak forest, and dense second-growth woodland.
Insects caught in the air or gleaned from foliage of trees and shrubs.
Populations appear stable or slightly declining.
- Lowther, P. E. 2000. Pacific-slope Flycatcher (Empidonax difficilis) and Cordilleran Flycatcher (Empidonax occidentalis). In The Birds of North America, No. 556 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.