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Mockingbirds and Thrashers

Mockingbirds, thrashers, and catbirds are 31 species of medium-sized birds that are sometimes known as mimid thrushes, in the family Mimidae. This is an American family of birds, occurring widely from southern Argentina and Chile, through to southern Canada. The usual habitat of mimids is brushlands, forest edges, shrubby riparian areas, and recently disturbed forests.

Mimids range in body length from 7.9-11.8 in (20-30 cm), and are slender-bodied, with short, rounded wings, a long tail, and long legs. The beak is rather heavy and downward curving, and in some species is quite long and strongly decurved.

Mimids have a rather subdued plumage, with most species colored in brown or gray hues, often with a light throat or underparts, and sometimes with a spotted or streaked breast. Some species are solidly colored, while others have patterns, especially of white on the wings and tail. The sexes do not differ significantly in size or coloration.

A curve-billed thrasher (Toxostoma curvirostre) perched near its nest in a cactus at the Arizona Sonora Desert Museum, Arizona. Photograph by Robert J. Huffman. Field Mark Publications. Reproduced by permission.

Mimids feed on invertebrates, berries, and seeds. They forage on the ground, or in shrubs. Mimids are not social birds, and do not gather into flocks.

Mimids are highly territorial during the breeding season, sometimes attacking nearby dogs, cats, other birds, and even people who stray too close to their defended area. Mimids are loud, and delightfully versatile singers. Some species are excellent mimics, and incorporate aspects of the songs of other species into their own individualistic, highly varied renditions.

Mimids build their rather bulky, cup-shaped, grass-lined, twiggy nests in shrubs, or sometimes on the ground. Mimids lay 2-6 eggs, which are incubated by the female, although the male helps in rearing the young.

The best-known mimid in North America is the northern mockingbird (Mimus polyglottos), an acclaimed songster of shrubby and suburban habitats that breeds over most of the United States and Mexico, some Caribbean islands, and southern Canada.

The brown thrasher (Toxostoma rufum) is a common, rufous-backed bird with a white, spotted breast. This species occurs widely in temperate regions of eastern North America. The sage thrasher (Oreoscoptes montanus) is a common species of dry habitats in southwestern North America. Some other thrashers have considerably longer and more decurved beaks, especially the California thrasher (Toxostoma redivivum) and LeConte's thrasher (T. lecontei), both of which occur in the southwestern United States.

The catbird (Dumetella carolinensis) is a gray-bodied, black-capped bird, with rusty-brown under the tail coverts (that is, where the tail joins the body). This species breeds from southern Canada through most of the United States, and winters as far south as Panama. The catbird is named after its alarm call, which sounds remarkably like the mewing cat. The song is much more melodious.

Bill Freedman

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