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> Brewer's Sparrow
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| Population
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16 million |
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Photo by Milo Burcham, U.S. Forest Service.
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Brewer's Sparrow
(Spizella breweri)
Brewer's Sparrows have been described as dull, nondescript, or subtle. While undoubtedly inconspicuous, they are often the most abundant summer birds in their favored sagebrush habitat. In the future, the Brewer's Sparrow may be split into two separate species - one subspecies, the Timberline Sparrow (S. b. taverneri), differs in appearance, song, and breeding range and habitat.
Identification
Brewer's Sparrows are small and slender with a long, notched tail. They have plain gray breasts, a finely streaked brown crown without an obvious central stripe, a dull gray eye line, and a thin but distinct pale eye ring.
Distribution and
Population Trends
Most Brewer's Sparrows breed in the western U.S. in plains and foothills, primarily in the Great Basin. The Timberline Sparrow (S. b. taverneri) breeds in mountains of southwest Alberta, Southeast British Columbia, northwest British Columbia through southwest Yukon, and southeast Alaska. In the U.S., Brewer's Sparrows winter in central and southern interior California, southern Nevada, central Arizona, southern New Mexico, and central and west Texas. The wintering range extends into central Mexico, including the Baja Peninsula of Mexico.
Populations of Brewer's Sparrows tend to fluctuate from year to year in any given locale. In suitable habitat, they are often abundant. Breeding Bird Survey data do indicate that numbers of this species have decreased since the early 1960s, with consistent declines noted from 1966 to 1996. Declines appear to be more pronounced since 1980.
Ecology
Brewer's Sparrows are closely associated with sagebrush, preferring dense stands broken up with grassy areas. Adults return persistently to the same breeding sites each year. In the northern part of their range, they can be found in habitats such as sub-alpine fir or dwarf birch, or montane pinon-juniper woodlands. Breeding takes place in mid-April through early August, and can occur in high densities. The nest is placed on or near the ground, and the male often helps with incubation. In the winter they favor low, dry vegetation, and Brewer's Sparrows can often be found in large, noisy flocks. They forage on or close to the ground.
Threats
Habitat destruction, alteration, and fragmentation impact populations of Brewer's Sparrows. This species requires habitat with a dense shrub component, and sagebrush control, such as used for range management, causes significant decreases in numbers. Sagebrush habitats can be difficult to restore if heavy grazing causes invasion by non-native plants and grasses, in particular cheatgrass. This altered habitat is also prone to fires that result in grass-dominated landscapes.
Conservation
Recent concern over conservation of various sagebrush dependent bird species including the Greater Sage-Grouse, should eventually benefit Brewer's Sparrows when concrete conservation actions are implemented.
What Can You Do?
Audubon's Important Bird Area program is a vital tool for the conservation of Brewer's Sparrow as well as other species. To learn more about the Important Bird Areas program and how you can help, visit: http://www.audubon.org/bird/iba/.
U.S. National Wildlife Refuges provide essential habitat for Brewer's Sparrow, and a great number of other species throughout the U.S. and its territories. Unfortunately, the refuge system is often under-funded during the U.S. government's budgeting process. To learn more about how you can help gain much needed funding for U.S. National Wildlife Refuges, visit: http://www.audubon.org/campaign/refuge_report/
Information on where Brewer's Sparrows occur and in what numbers is vital to conserving the species. Help in monitoring this and other species by reporting your sightings to eBird. A project of Audubon and the Cornell Lab of Ornithology, eBird is the world's first comprehensive on-line bird monitoring program: http://www.audubon.org/bird/ebird/index.html.
Volunteers are crucial to the success of programs that monitor the status of populations of Brewer's Sparrow and other bird species. Audubon's Christmas Bird Count (CBC) is one of the longest-running citizen-science monitoring programs in the world and has helped to follow changes in the numbers and distribution of Brewer's Sparrow. To learn more about the CBC and how you can participate, visit: http://www.audubon.org/bird/cbc.
References
Beadle, D. and J. Rising. 2002. Sparrows of the United States and Canada: The Photographic Guide. Academic Press, San Diego, CA.
Byers, C., J. Curson, and U. Olsson. 1995. Sparrows and Buntings. Houghton Mifflin Co., New York.
Faanes, C. A. and G. R. Lingle. 1995. Breeding birds of the Platte River Valley of Nebraska. (http://www.npwrc.usgs.gov/resource/distr/birds/platte/platte.htm) Version 02SEP99. Northern Prairie Wildlife Research Center, Jamestown, ND.
Paige, C. 1999. Brewer's Sparrow species management abstract. The Nature Conservancy, Arlington, VA.
Rising, J. 1996. A Guide to the Identification and Natural History of the Sparrows of the United States and Canada. Academic Press, San Diego, CA.
Rotenberry, J. T., M. A. Patten, and K. L. Preston. 1999. Brewer's Sparrow (Spizella breweri). In The Birds of North America, No. 390 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C.
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