The vesper sparrow, Pooecetes gramineus, breeds in Canada and the northern United States, and winters in the southern United States and most of Mexico. This species is common during summer throughout Utah and is rare during winter in the southwestern corner of the state. Its habitats are dry grasslands and sagebrush. Its diet consists of about half insects and about half grass and forb seeds.
The vesper sparrow nests on the ground, often near patches of vegetation. The three or four eggs are incubated, mainly by the female parent, for eleven to thirteen days. The nestlings, tended by both parents, leave the nest after nine to thirteen days, but are dependent upon the parents (usually the male) for another twenty to twenty-two days. This species is commonly the victim of brood parasitism by the brown-headed cowbird.
Baicich, P. J., and C. J. O. Harrison. 1997. A guide to the nests, eggs, and nestlings of North American birds. 2nd ed. Academic, San Diego. 347 pp.
Ehrlich, P. R., D. S. Dobkin, and D. Wheye. 1988. The birderís handbook[:] a field guide to the natural history of North American birds. Simon & Schuster, New York. xxx + 785 pp.
Behle, W. H., E. D. Sorensen, and C. M. White. 1985. Utah birds: a revised checklist. Utah Museum of Natural History, University of Utah, Salt Lake City. vi + 108 pp.