SPECIES

Bendire's Thrasher Toxostoma bendirei Scientific name definitions

A. Sidney England and W. F. Laudenslayer Jr.
Version: 1.0 — Published March 4, 2020
Text last updated January 1, 1993

Identification

Field Identification

Medium-sized songbird; smaller than other sympatric, congeneric thrashers. Total length of males 23.2-24.7 cm, females 22.7-24.7 cm (2); mass about 60 g. Separable from other North American passerines except thrashers by combinations of the following characters: medium size; wings relatively short and rounded; 10 primaries; tarsi scutellate on anterior surface; bill acuminate, upper mandible not hooked over lower mandible, and culmen weakly decurved distally; coloration on crown, back, wings, and tail relatively uniform (i.e., lacks distinct spotting, streaking, barring, and wingbars, though feather edges may be lighter in fresh feathering); external nares not covered by feathers; and tail as long or longer than body.

Distinguishable from most potentially sympatric thrashers by combinations of the following characters (see also Appendix 1): dorsal coloration relatively uniform dark drab to olive-brown; white markings on tail feathers limited to corners of outer rectrices (may be absent in worn plumage); distinct white wingbars and wing patches lacking; iris yellow to orange-yellow; short, thin, upward-pointing, triangular spots on breast arranged in distinct streaks on upper breast, less distinct on lower breast, and may extend faintly onto sides (all streaks and spots may be absent in worn plumage); and bill relatively short, not conspicuously decurved, upper mandible dark gray and slightly decurved distally, and lower mandible nearly straight and pale towards base.

Similar Species

Most similar to Sage Thrasher (Oreoscoptes montanus), Gray Thrasher (T. cinerium), and Curve-billed Thrasher especially in worn and faded feathering during the late spring and summer prior to molt in the fall (3, 4, 4). Sage Thrasher is smaller and has a shorter, straighter bill. Bill and eye color, and tail markings similar to Bendire's Thrasher. Sage Thrasher has heavy streaking on breast (sometimes extending to sides and abdomen) and white wingbars which may not be prominent even in freshly molted feathering. Both characters fade considerably by late spring, but in all seasons show more contrast than Bendire's Thrasher.

Bold, nearly black, teardrop-shaped spots and streaks on underside of Gray Thrasher extend from breast to flanks; contrast apparent even in worn plumage. Flanks and rump tinged with cinnamon-rufous.

Curve-billed Thrasher larger than Bendire's. Bill of adult Curve-billed relatively long and decurved; bill of immature birds may be as short and straight as Bendire's. Bill color usually black in adult and immature Curve-billed Thrashers but some individuals may be pale towards base (4) and light yellow gape of immatures may be confused with pale horn color at base of bill in Bendire's Thrasher. At all ages, gonyeal angle (where the upper and lower beak meet) is rounded in Bendire's and acutely angled in Curve-billed (5). Spots on breast of adults roughly circular, may be triangular in center of lower breast; less distinct from background color than in Bendire's Thrasher; and generally more distinct in T. c. curvirostre than in T. c. palmeri, and generally do not coalesce to form streaks. Juvenile Curve-billed have distinct, triangular marks on breast. Iris generally yellow in Bendire's but some individuals orange-yellow; Curve-billed generally orange in adult T. c. curvirostre but more yellow in T. c. palmeri and can be yellow in immatures.

Recommended Citation

England, A. S. and W. F. Laudenslayer Jr. (2020). Bendire's Thrasher (Toxostoma bendirei), version 1.0. In Birds of the World (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.benthr.01