ALDER FLYCATCHER Empidonax alnorum Brewster, 1895

Accepted: 4 (22%)	Treated in Appendix H: yes
Not accepted: 14	CBRC review: all records
Not submitted/reviewed: 1	Color image: none

This small flycatcher’s northern breeding limit extends from central Alaska and central British Columbia east to Labrador and Newfoundland. The southern limit reaches from northern North Dakota east to Connecticut and south very locally in the Appalachian Mts. from Pennsylvania to North Carolina. Most fall migrants pass around or over the western Gulf of Mexico, avoiding the southeastern Atlantic coast, then continue south through eastern Mexico to winter in South America. The species is casual or accidental in northern Alaska, Washington, Baja California Sur (15 May 1911, Howell et al. 2001), Iceland (BW 16:435-440), Bermuda, and the West Indies. In the East, this species’ spring passage is very late (mostly late May to early June), and the fall passage is early (mostly August to mid September). The species’ range and migratory habits suggest that it should be a more regular vagrant through the Pacific coast states, particularly in fall, but its true status remains an enigma. Patten et al. (1995) reviewed the Alder Flycatcher’s known status in the West.

California’s first record of the Alder Flycatcher involves a first-fall female collected on 2 September 1987 at Southeast Farallon Island—a record that the CBRC only recently accepted with confirmation by Philip Unitt of the San Diego Natural History Museum. The second record, involving another young bird in early fall at Southeast Farallon Island, was documented with in-hand photographs and measurements. The Committee has grappled with other similarly well-documented records, ultimately leaving their identification unresolved. The state’s other two CBRC-endorsed records involve singing birds in Kern County (cf. the Yellow-bellied Flycatcher account); see also Appendix H. In addition, Lowther (1999) and Patten et al. (2003) published the specimen record of a first-fall bird collected on 28 September 1991 near Westmorland, Imperial County; the Committee has not reviewed this record.

Silent Alder Flycatchers are among North America’s most difficult birds to identify with certainty, as they are very similar to the nominate eastern subspecies of the Willow Flycatcher (Stein 1963, Hussell 1990, Browning 1993, Pyle 1997a, 1997b). The Committee has reviewed several spring (28 May–16 June) and fall (4 September–2 November) records of Alder-like birds, some of which gave peet call notes (see LeGrand 1979, Lehman 1985, Whitney and Kaufman 1986, Kaufman 1990), but records not supported by diagnostic vocalizations or unequivocal in-hand data have stood little chance of receiving CBRC endorsement, given current knowledge.