Zonotrichia leucophrys

Five subspecies are recognized: Zonotrichia leucophrys leucophrys, Z. l. gambelii, Z. l. oriantha, Z. l. pugetensis and Z. l. nuttalli. Substantial gene flow occurs between subspecies pugetensis and nuttalli (Corbin and Wilkie 1988).

Mitochondrial DNA data indicate that relative to most congeneric avian comparisons, the five species of Zonotrichia are closely related; leucophrys is most closely related to the Golden-crowned Sparrow, Z. atricapilla (Zink et al. 1991).

Large range in North America; abundant; secure.

Breeding range extends from northern Alaska to Labrador, south to southern California, Nevada, central Arizona, northern New Mexico, central Manitoba, southeastern Quebec, and Newfoundland. The five recognized subspecies are fairly distinct in their distributions, with very little overlap of breeding areas (Morton 2002). Subspecies nuttalli is a nonmigratory resident of coastal California; pugetensis breeds along the Pacific coast from northern California to southern British Columbia; oriantha breeds in the central western United States and the Sierra Nevada; leucophrys breeds across northern Quebec, Labrador, and Newfoundland; and gambelii breeds throughout Alaska east to northwestern Ontario and south to southcentral British Columbia (Dunn et al. 1995).

During the nonbreeding season, the species ranges casually to central and southcentral Alaska and occurs regularly from southern British Columbia, southeastern Washington, southern Idaho, Wyoming, Kansas, Missouri, Kentucky to western North Carolina, south to southern Baja California and southern mainland of Mexico, Gulf coast, and Cuba. Subspecies pugetensis winters along the Pacific coast from Washington to southern California; oriantha winters from the southern U.S. border to Baja California and southern Mexico; leucophrys winters in the eastern United States north to the Great Lakes and rarely in New England north to Massachusetts; and gambelii winters throughout the western United States and sparsely in the eastern United States (Dunn et al. 1995).

This species is represented by a very large number of occurrences (subpopulations).

Few threats exist overall. In some areas there is concern related to brood parasitism by the brown-headed cowbird (Trail and Baptista 1993), habitat alteration due to cattle grazing (Favis 2000), and natural mortality caused by predation (Morton et al. 1993, Chilton et al. 1995) and inclement weather (Morton 2002).

Cowbird parasitism is not a problem in most areas, but in the San Francisco Bay area, subspecies nuttalli experienced a large increase in the rate of brood parasitism that could threaten long-term population persistence (Trail and Baptista 1993).

Although this species utilizes disturbed areas during the breeding season, disturbance as a result of cattle grazing has been shown to have a negative effect on sparrow populations. Reduced nest success in California coastal scrub communities (compared to undisturbed habitat) was attributed to habitat alteration as a result of grazing (Favis 2000).

Predation contributes substantially to egg and nestling mortality in some populations (Chilton et al. 1995). Predation by Belding's ground squirrels (Spermophilus beldingi) was the largest cause of nest failure during a 19-year study in the Sierra Nevada, California (Morton et al. 1993).

Activities of human investigators may also increase the likelihood of nest predation and desertion (Morton et al. 1993; Chilton et al. 1995). Nest loss and desertion also have been attributed to weather effects such as late spring snowfall (Morton 2002).