Click image for enlargement.

Figure 270. The CBRC reviewed records of the Brown Thrasher only in 1972. With a detection rate of about a half-dozen per year, this species just barely misses a place on the Committee’s review list. This first-fall bird was photographed on 23 October 1994 at Galileo Hill, Kern County (Larry Sansone).

 

Figure 384. The Brown Thrasher reaches California primarily as a very rare fall vagrant. One such bird was photographed during October 2002 at Galileo Hill in Kern County (Bob Steele).

 

 

 

 

 

BROWN THRASHER Toxostoma rufum (Linnaeus, 1758)

Accepted: 2 (100%)	Treated in Appendix H: no
Not accepted: 0	CBRC review: 1972 records1
Not submitted/reviewed: NA	Large color image: see Figures

This thrasher’s northern breeding limit extends from central Alberta east to southern New Brunswick. The southern limit reaches from eastern Texas to southern Florida. The species winters from the Southeast northward to south-coastal New England and westward through most of Texas to southeastern New Mexico. Birds winter casually across most of the United States and in southern Ontario. Migrants occur casually west of the breeding range, from southern British Columbia south to Nayarit, and extralimital records extend to northern Alaska, northern Manitoba, northern Hudson Bay, Tamaulipas, the Bahamas, western Cuba, Bermuda, the Netherlands Antilles, the British Isles, and Germany.

California’s first Brown Thrasher was recorded in September 1870 by James G. Cooper—namesake of the Cooper Ornithological Society—at Clear Lake in Lake County (Baird et al. 1874, Cooper 1877). Grinnell (1915) initially doubted this record’s veracity, but eventually accepted it (Grinnell and Miller 1944:347), along with three winter records of birds banded in Los Angeles County during the 1930s and 1940s. The first specimen refers to a first-fall male secured on 22 October 1945 at Cottonwood Spring in Riverside County (Russell 1947, MVZ 94277). Records of the Brown Thrasher were reviewed only in 1972, when it was recognized as a very rare but regular migrant that occasionally winters in the state. Roberson (1980) reported 84 California records by the end of the 1970s, 15% of them during winter. From 1984 to 2003, records averaged about seven per year in California, but the rate declined during that period. From 1968 to 1999, the average on Southeast Farallon Island was just 0.4 per fall and 0.3 per spring (Richardson et al. 2003).

When presented with any apparent rarity, observers are encouraged to keep an open mind when making the identification, to be sure that all possible alternatives are ruled out. In the case of an evident Brown Thrasher in California, one must rule out the similar Long-billed Thrasher (T. longirostre) of southern Texas and eastern Mexico. Although the Long-billed Thrasher is non-migratory, a few have been found north and west of the normal range, with records from New Mexico and Colorado. Whereas the Long-billed Thrasher can hardly be expected in California, the same might be said of species such as the Blue Mockingbird and Black-backed Oriole, both of which managed to reach the state one way or another.

¹On the review list 1972–1973