Figure 377. Seasonal occurrence of the Gray-cheeked Thrush in California, showing a sharp spike from mid September to mid October and a minor pattern of spring occurrence in late May and early June.

 

Figure 378. This Gray-cheeked Thrush, banded on 10 September 1990 at Pt. Loma in San Diego County, is one of only four recorded in southern coastal California ( 1990-133; Guy McCaskie).

 

Figure 379. Both of California’s inland records of the Gray-cheeked Thrush refer to fall vagrants at Galileo Hill in eastern Kern County. This first-fall bird, aged by pale tips to the greater secondary coverts, was sketched there on 9 October 1998 (1998-184; John C. Wilson).

 

 

 

 

 

 

 

 

GRAY-CHEEKED THRUSH Catharus minimus (Lafresnaye, 1848)

Accepted: 21 (81%)	Treated in Appendix H: no
Not accepted: 5	CBRC review: all records
Not submitted/reviewed: 4	Color image: none

This thrush breeds in extreme northeastern Siberia and from Alaska east across northern Canada to Newfoundland. The species winters from Colombia to Brazil (rarely to Panama, casually to Costa Rica) and migrates primarily through the central and eastern United States, across the Gulf of Mexico and western Caribbean Sea, and through southern and eastern Middle America. The specimen record of a weakened bird collected on 8 December 1981 in southern Ontario (McRae 1984), which the AOU (1998) listed as a “winter” record, should more correctly be referred to as a very late fall migrant (A. Wormington in litt.). Vagrants occur casually or accidentally in the Aleutian and Pribilof Islands and along the Pacific coast, with single records from southern British Columbia and Washington, two from Oregon, one from Isla Guadalupe (Quintana-Barrios et al. 2006), and two or three from Clipperton Atoll (Howell et al. 1993). Additional records of vagrants come from Idaho, Arizona, New Mexico, Martinique, eastern Peru, Greenland, and Europe.

California’s first Gray-cheeked Thrush was a first-fall male collected on 3 October 1970 on Southeast Farallon Island (DeSante and Ainley 1980). A remarkable 71% of records (15 of 21) come from this location and nearby Pt. Reyes, Marin County. Apart from two late spring records (28 May–11 June, both from Southeast Farallon Island), all records fall between 10 September and 31 October (Figure 377). Two fall records from Galileo Hill in eastern Kern County, 14–18 September 1989 and 9 October 1998 (Figure 379), furnish the only ones from the state’s interior. Considering that this thrush breeds extensively in western Canada, Alaska, and extreme northeastern Siberia and migrates long distances to the neotropics, its extreme rarity in California is surprising (see the preceding account).

After the CBRC reviewed many of the state’s Gray-cheeked Thrush records, Bicknell’s Thrush (C. bicknelli) was accorded species status on the basis of minor differences in song and morphology (Ouellet 1993, AOU 1995, cf. Marshall 2001). The documentation for several California records has eliminated Bicknell’s Thrush, but not all records have been reviewed with this goal in mind. Considering the population sizes, distributions, and migratory pathways of these two taxa, Gray-cheeked is vastly more likely to occur in California (Bicknell’s has yet to be recorded in central or western North America). Identification of these putative sibling species is extremely difficult, and probably impossible under most field conditions; see references by Ouellet (1993), Curson (1994), McLaren (1995), Knox (1996), Pyle (1997b), and Marshall (2001) for more information.

Lane and Jaramillo (2000b:247) cautioned against confusing a Gray-cheeked Thrush with a dark Veery.