Cassin's Sparrow

The Cassin's sparrow (Peucaea cassinii) is a medium-sized, unassuming sparrow with a fairly large, plain, grayish appearance and a long, rounded tail. It is a bird that lacks conspicuous markings, making it somewhat elusive to the untrained eye.

Identification Tips

Adult Cassin's sparrows have a brown streaked head with gray and dark brown, a buff supercilium, and a thin, dark brown submoustachial stripe. Their bill is brownish gray, and the iris is dark brown. The chin, throat, and breast are pale gray or brownish gray, with the belly being whitish. The back features a mantle and scapulars that are brown or gray with a rusty tinge, and the wings are brown with a wing bar that can range from fairly conspicuous to indistinct. The tail is dark, dusky brown, with the central two rectrices being paler and sometimes showing faint crossbars. Juveniles resemble adults but have brown backs with buffy tips and darker brown central streaks.

Habitat

Cassin's sparrows are commonly found in brushy grasslands and exhibit nomadic tendencies. They require habitats with both a grass component and a shrub component, such as mesquite, sage, hackberry, rabbitbrush, or oaks.

Distribution

This passerine bird's range extends from western Nebraska to north-central Mexico. It is more commonly found in south-central states, with its presence in the northern part of its range being rare and possibly influenced by rainfall patterns.

Behaviour

Cassin's sparrows are known for their skylarking behavior during the breeding season, where males perform a dramatic flight display. They are generally secretive but can become more accommodating to observers, especially early in the breeding season. They forage mostly on the ground in open areas and may flush to a bush or fence when disturbed.

Song & Calls

The primary song of the Cassin's sparrow is a distinctive six-note complex, starting with a soft introductory note followed by a long, high musical trill and usually two lower, well-spaced musical notes. Males are known for their skylarking flight songs, ascending from a perch and singing as they glide down. They also have a secondary "chitter" song and various calls used for communication and alarm.

Breeding

The nest of the Cassin's sparrow is constructed in grass from a mixture of weeds and grasses. The female typically lays 3 to 5 eggs. Their breeding behavior is closely tied to their skylarking and singing activities.

Similar Species

Cassin's sparrow resembles Botteri's sparrow in size and markings, but Botteri's sparrow is a weaker shade of gray. The most reliable way to differentiate the two species is by the song of Cassin's sparrow.

Diet and Feeding

Cassin's sparrows primarily feed on insects such as grasshoppers, caterpillars, and beetles during the summer, with the young being fed almost exclusively on insects. In fall and winter, they consume seeds of weeds and grasses. They forage on the ground and occasionally glean from shrubs.

Conservation Status

The Cassin's sparrow is currently listed as Least Concern on the IUCN Red List, indicating that it is not at immediate risk of population decline or extinction.