Brown Thrasher Toxostoma rufum Scientific name definitions

This thrasher, the only one east of the Rocky Mountains and central Texas, inhabits thickets and hedgerows in deciduous forest clearings and forest edge in the eastern United States. Farther west, within the Great Plains, it commonly breeds in fencerows, shelterbelts, and woody draws. Because of its tendency to forage on the ground and skulk in dense brush when disturbed, it is less often seen than heard. Although not as well recognized for its vocal abilities as the Northern Mockingbird (Mimus polyglottos), it is a remarkable singer with one of the largest repertoires of any North American passerine.

Brown Thrashers have long, heavy legs, characteristic of a ground foraging bird, and spend considerable time sweeping the litter and soil layer for insects, fallen seeds, and berries. The long, slightly curved bill of this species is generally used to uncover prey items with rapid side-to-side motions. During the breeding season (May–June), individuals feed chiefly on insects and other arthropods, but by late summer rely more heavily on fruit and berries.

Pairs usually nest low in a tree or shrub, occasionally on the ground. Both sexes incubate the clutch of 3–5 eggs and feed young, which fledge relatively quickly for a passerine of this size, sometimes leaving the nest fully feathered in 9 days—an adaptation that may help reduce high rates of nest predation commonly seen in shrub-nesting species. Brown Thrashers are the largest common host of Brown-headed Cowbirds (Molothrus ater), although they often reject the eggs of this parasite.

Systematic relationships to other thrashers are discussed in Engels 1940 Engels, W. (1940). Structural adaptations in thrashers (Mimidae: genus Toxostoma) with comments on interspecific relationships. University of California Publications in Zoology 42:341-400. Close , Mayr and Short 1970 Mayr, E., and L. L. Short (1970). Species taxa of North American birds: A contribution to comparative systematics. Publications of the Nuttall Ornithological Club 9, Cambridge, MA, USA. Close , Klicka and Zink 1997 Klicka, J. and R. M. Zink. (1997). The importance of recent ice ages in speciation: A failed paradigm. Science 277 (5332):1666-1669. Close , and Zink et al. 1999 Zink, R. M., D. L. Dittmann, J. Klicka and R. C. Blackwell-Rago (1999). Evolutionary patterns of morphometrics, allozymes, and mitochondrial DNA in thrashers (genus Toxostoma). Auk 116 (4):1021-1038. Close . Information on many aspects of breeding biology are available from studies in Kentucky (Partin 1977 Partin, H. (1977). Breeding biology and behavior of the Brown Thrasher (Toxostoma rufum). Phd Thesis, Ohio State Univ., Columbus. Close ), Tennessee (Erwin 1935 Erwin, W. G. (1935). Some nesting habits of the Brown Thrasher. Journal of the Tennessee Academy of Science 10:179-204. Close ), Iowa (Gabrielson 1912 Gabrielson, I. N. (1912). A study of the home life of the Brown Thrasher, Toxostoma rufum (Linn.). Wilson Bulletin 24:65-94. Close ), North Dakota (Haas Haas 1985 Haas, C. A. (1985). New nesting dates for Brown Thrashers, Loggerhead Shrikes, and American Robins in North Dakota. Prairie Naturalist 17:249-250. Close , Haas 1990 Haas, C. A. (1990). Breeding ecology and site fidelity of American Robins, Brown Thrashers, and Loggerhead Shrikes in shelterbelts in North Dakota. Phd Thesis, Cornell Univ., Ithaca, NY. Close , Haas 1995 Haas, C. A. (1995). Dispersal and use of corridors by birds in wooded patches on an agricultural landscape. Conservation Biology 9:845-854. Close , Haas 1997 Haas, C. A. (1997). What characteristics of shelterbelts are important to breeding success and return rate of birds? American Midland Naturalist 137:225-238. Close ; Haas and Haas 1998 Haas, C. A. and K. H. Haas. (1998). Brood parasitism by Brown-headed Cowbirds on Brown Thrashers: frequency and rates of rejection. Condor 100:535-540. Close ), and Kansas (Cavitt Cavitt 1998 Cavitt, J. F. (1998). The role of food supply and nest predation in limiting reproductive success of Brown Thrashers (Toxostoma rufum): effects of predator removal, food supplements and predation risk. Phd Thesis, Kansas State Univ., Manhattan. Close , Cavitt 1999 Cavitt, J. F. (1999). Effects of prairie fire and grazing on Brown Thrasher nest predation. Proc. N. Am. Prairie Conf. 16:112-119. Close ; Cavitt et al. 1999 Cavitt, J. F., A. T. Pearse and T. A. Miller. (1999). Brown Thrasher nest reuse: a time saving resource, protection from search-strategy predators, or cues for nest-site selection. Condor 101:859-862. Close ). Winter ecology is known from a single study in Texas (Fischer Fischer 1981a Fischer, D. H. (1981a). Winter time budgets of Brown Thrashers. Journal of Field Ornithology 52:304-308. Close , Fischer 1981b Fischer, D. H. (1981b). Wintering ecology of thrashers in southern Texas. Condor 83:340-346. Close ).

Even though this species is widespread in eastern North America, much remains to be learned about its behavior and ecology, particularly during the nonbreeding season. Future studies of migration routes, control and physiology of migration and orientation, foraging ecology, and reproductive biology (particularly geographic variation, fledgling behavior, and development) will be valuable.