Cassin’s Sparrow
At a Glance
In dry grassland country of the Southwest in summer, this plain brown sparrow is often seen flying up from a bush top and then fluttering down in a 'skylarking' display, giving a song of sweet trills and notes. Cassin's Sparrows are sometimes very common, but they are irregular, big numbers often appearing in an area after good rains have turned the prairies green. With their nomadic tendencies, they sometimes turn up far outside their normal range, with scattered records from coast to coast.
All bird guide text and rangemaps adapted from Lives of North American Birds by Kenn Kaufman© 1996, used by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Category
New World Sparrows, Perching Birds
IUCN Status
Least Concern
Habitat
Desert and Arid Habitats, Fields, Meadows, and Grasslands, Shrublands, Savannas, and Thickets
Region
Plains, Rocky Mountains, Southwest, Texas
Behavior
Direct Flight, Flitter, Running
Population
14.000.000
Range & Identification
Migration & Range Maps
In many areas, seasonal occurrence is very irregular; may be present in large numbers one summer, absent the next. Winter numbers in Southwest are also quite variable. Strays sometimes wander far, having reached eastern Canada.
Description
5 3/4" (15 cm). Long-tailed, gray-brown, confusingly plain. Dull white tail corners; dark marks on back and flanks can be obscure in faded summer plumage. Best known by habit of fluttering up in air and gliding back down while singing.
Size
About the size of a Sparrow
Color
Black, Brown, Gray, White
Wing Shape
Broad
Tail Shape
Rounded, Square-tipped
Songs and Calls
4 loud, melodious, clear whistles, uttered from the tops of tall grass stalks and also in flight. Second note is prolonged and quavering; third note is lowest.
Call Pattern
Falling
Call Type
Chirp/Chip, Trill, Whistle
Habitat
Desert grassland, brushy fields. Breeds in a variety of situations having good ground cover of grass and low shrubs; ranges from open grassland with only scattered shrubs to brushy areas with grassy understory. In migration and winter, also found in pure grassland, brushy areas, deserts.
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Behavior
Eggs
3-5, usually 4. White, unmarked. Details of incubation are not well known.
Young
Both parents feed the nestlings. Age at which young leave the nest is not well known.
Feeding Behavior
Forages mostly or entirely on the ground, hopping about in relatively open areas, taking items from the ground or from plant stems.
Diet
Mainly insects and seeds. Summer diet is partly to mostly insects, especially grasshoppers, caterpillars, moths, and beetles, also many others. Young are fed almost entirely on insects. Also eats seeds, especially in fall and winter, mainly those of weeds and grasses.
Nesting
Somewhat irregular in its nesting, especially in western and northern parts of range; may appear in numbers and breed only in years with good rainfall. Male advertises territory with flight song display, flying up to about 20' and then gliding and fluttering down, while singing. In courtship, male may chase female, or may display with wings and tail partly spread and fluttering. Nest site is usually on the ground, well hidden among weeds or at the base of a bush. Sometimes up to a foot above ground in a low shrub. Nest is an open cup made of dry grass, weed stems, bark, plant fibers, lined with fine grass.
Climate Vulnerability
Conservation Status
Great variation in annual numbers makes it difficult to monitor overall population. Apparently still widespread and common.
Climate Threats Facing the Cassin's Sparrow
Choose a temperature scenario below to see which threats will affect this species as warming increases. The same climate change-driven threats that put birds at risk will affect other wildlife and people, too.