Worthen's Sparrow

Spizella wortheni can range in length from 12.5 to 14 cm. It is identifiable by its distinctive head pattern. It has a grey head with a rufous crown, a brown postocular stripe and a pink bill. It has grey-brown upperparts, with dark brown streaks. It has a grey bottom, and dark brown wings and tail. Its wings are "edged paler, with broad whitish to pale buff wing-bar, buffy-rufous tertial and secondary edging, and greyish lesser coverts". Juveniles are characterized by brownish colouration of the head and chest, with dusky streaking on the head and dark brown streaking on the chest and flanks.

The song is a dry, chipping trill of 2–3 seconds duration and is described as a cross between that of the field sparrow and that of the chipping sparrow. The species is similar in appearance to the field sparrow (Spizella pusilla). However, they differ in plumage, habitat, and song. The species nests from May to July and usually lays three or four eggs. Single-species flocks form after the breeding season and are strongly attracted to permanent sources of water. The species is not migratory; however, a few sightings of individuals have taken place throughout the northwestern region of Mexico. Only one individual has ever been identified (shot) in the United States, and it was by Rieber on June 16, 1884, near Silver City, New Mexico. …

Worthen's sparrow is endemic to northeastern Mexico and currently occupies a 25 km2 range. Populations formerly occurred in Zacatecas, Coahuila, Nuevo León, and Tamaulipas; however, presently it is only known to occur from southeastern Coahuila to western Nuevo León. Spizella wortheni prefers open, arid shrub-grassland at elevations of 1,200–2,450 m (3,940–8,040 ft). For foraging, the species prefers open areas with low grasses. For nesting and cover, it usually inhabits low, dense shrubs. In 2004, the population was estimated to be 100–120 individuals.