Curve-billed Thrasher, Toxostoma curvirostre

Curve-billed Thrasher, Toxostoma curvirostre maculatum. Photographs taken within a residential community in Alamos, Sonora, January 2018 and 2019. Photographs and identification courtesy of David F Smith, Alamos, Sonora.

Curve-billed Thrasher, Toxostoma curvirostre maculatum. Photograph taken within a residential community in Hereford, Arizona, November 2020. Photograph and identification courtesy of Bob Behrstock, Sierra Vista, Arizona (naturewideimages.com).

The Curve-billed Thrasher, Toxostoma curvirostre maculatum, is one of seven subspecies of Curve-billed Thrasher, and all seven are permanent residents of Mexico. They are a member of the Mimidae Family of Mockingbirds and Thrashers, which has thirty-four members place in ten genera, and one of as ten global species of the Toxostoma Genus. They are known in Mexico as cuitlacoche de pico curvo.

The Curve-bill Thrasher is similar in stature to the American Robin, but slimmer, heavy legged, with a long tail that is slightly rounded with a blunt tip. Their overall plumage color is grayish-brown with a white throat white. Their underparts are rusty-brown that deepens on the rump and out webs of the secondaries. They have brown spots across the chest and there is a rusty tinge across the breast, along the sides and over the anal region. Their bill is long, slender, blackish, and decurved. Their wings are brown with broad white tips.

The Curve-bill Thrasher within semi-open arid habitats with cacti and shrubs of the coastal plain and foothills. They are found at elevations between below 1,400 m (4,600 feet). They are ground forages that feed primarily on insects and seasonal berries, cacti fruit and seeds. They are non-migratory with life spans of up to eleven years. They have a loud, distinctive double whistle. The Curved-bill Thrasher is poorly studied, and their behavioral patterns are not poorly documented.

The Curve-bill Thrasher is found throughout northern Mexico and in the interior away from the coasts extending as far south as Mexico City. The maculatum subspecies is found in western Mexico within the Pacific Slope of southwest Chihuahua and Sonora.

The Curve-bill Thrasher is difficult to distinguish from the Bendire’s Thasher, Toxostoma bendirei, the Crissal Thrasher, Toxostoma crissale, and Le Conte’s Thrasher, Toxostoma lecontei, in areas with overlapping ranges.

From a conservation perspective the Curve-billed Thrasher, is currently considered to be of Least Concern, with stable widely distributed populations. Their populations are being adversely affected by the conversion of grass and woodland in Sonora, to Buffel Grass, Pennisetum cituare, which is highly invasive and taken over and has become a monoculture in many areas.