Physical characteristics

The 35 species of mimid (Peter's checklist lists 13 genera and 31 species, but a more recent classification is used here) share many common characteristics. All are, for passerines, quite large, typically of a size similar to a Eurasian blackbird (Turdus merula) or American robin (Turdus migratorius). Legs and feet tend to be stout and sturdy, the tail long and graduated, the wings generally rather short and rounded. The bill is always relatively large, sometimes long and decurved. Coloration is usually fairly muted; most species are various shades of gray or brown (often brightly rufous), or in some cases

A northern mockingbird (Mimus polyglottos) bathes in south Texas. (Photo by Joe McDonald. Bruce Coleman Inc. Reproduced by permission.)

blue. Bright greens, yellows, and reds are absent, although in several species the irides are a startling red or orange. Sexes are similar. The two largest groups within the Mimidae are the thrashers, genus Toxostoma, with 11 or 12 (according to accepted taxonomy) species, and the mockingbirds, genus Mimus, with 9 or 10 species. Thrashers tend to be heavy, often largely terrestrial species, sometimes heavily spotted below, with strong and often markedly decurved bills. In plumage, mockingbirds tend to be various shades of gray, often with conspicuous white flashes on wings and tail; the bill is more thrush-like, not strongly decurved. A closely allied genus, Nesomimus, is endemic to the Galápagos Islands; the four species are very similar, a generally brown-gray plumage with darker markings. Catbirds comprise two species; one, highly migratory, occurs all over eastern North America, the second, sedentary, is confined to Guatemala, Belize, and the Yucatán Peninsula of Mexico.

The greatest diversity of physical form is found in the West Indies where there are several unique island forms. The bizarre tremblers, found only in the Lesser Antilles, are the most aberrant mimids, with a fine, decurved bill (longer in the female) and an extraordinary habit of shaking and trembling the wings. Also endemic to the Lesser Antilles (two islands only) is the striking and endangered white-breasted thrasher (Ramphocinclus brachyurus,) with blackish upperparts, white underparts, and a red eye.

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