Breeds in humid coniferous forests and dense second-growth woodland (AOU 1998). Associated with streams, ravines, shade, and flight space below the canopy (Johnson 1980, Small 1994). Warm forest and woodland, especially in vicinity of shaded cliffs, stream banks, and human dwellings; in winter mostly in mixed woodland and humid lowland forest (AOU 1989). Nests along streams; flexible in choice of nesting substrate; nests in cliffs, in tree cavities, crotch of branch, earth banks, or on building ledges. In southeast Alaska, highest densities were found in areas with > 60% needleleaf forest cover (Cotter and Andres 2000). In BC, inhabit old-growth and mature second-growth Douglas fir-western hemlock and mixed coniferous-deciduous forests (Campbell et al. 1997).
AOU. 1989. Thirty-seventh supplement to the American Ornithologists’ Union Checklist of North American birds. Auk 106:532-538.
AOU. 1998. Check-list of North American birds. Seventh edition. American Ornithologists’ Union, Washington, D.C. 829 pp.
Campbell, R. W., N. K. Dawe, I. McTaggart-Cowan, J. M. Cooper, G. W. Kaiser, M. C. E. McNall, and G. E. J. Smith. 1997. The Birds of British Columbia. Volume 3. Passerines: flycatchers through vireos. University of British Columbia Press, Vancouver. 693 pages.
Cotter, P. A. and B. A. Andres. 2000. Breeding bird habitat associations on the Alaska Breeding Bird Survey: USGS, Biological Resources Division Information and Technology Report USGS/BRD/ITR-2000- 0010, 53 p.
Johnson, N.K. 1980. Character variation and evolution of sibling species in the EMPIDONAX DIFFICILIS- FLAVESCENS complex (Aves: Tyrannidae). Univ. Calif. Publ. Zool. 112. 151 p.
Small, A. 1994. California birds: their status and distribution. Ibis Publ. Co., Vista, CA.