Male Incubation and Multiple Brooding in Sagebrush Brewer’s Sparrows PDF Format - [748KB] ACKNOWLEDGMENTS: We thank K. Dust, S. Paczek, R. Gill, S. Weech, C. Elner, M. Lemon, H. van Oort, D. Higgins, P. Sandiford, S. Cox, and the Washington Shrub-steppe Bird Research Team for able field assistance, and C. Schneider and the Nature Trust of British Columbia for access to study sites. Financial support in British Columbia was provided by Environment Canada, Endangered Species Recovery Fund, Habitat Conservation Trust Fund, Human Resources Development Canada, Government of Canada Youth Internship Program, and the Natural Science and Engineering Research Council, and in Washington from the National Fish and Wildlife Foundation, the Washington Dept. Fish and Wildlife, and the Washington Dept. Natural Resources. We thank K. L. Petersen and two anonymous reviewers for thoughtful comments.

Male Incubation and Multiple Brooding in Sagebrush Brewer’s Sparrows Nancy A. Mahony - Centre for Applied Conservation Research, Univ. of British Columbia W. Matthew Vander Haegen - Washington Department of Fish and Wildlife Brett L. Walker - Div. of Biological Sciences, Univ. of Montana Pamela G. Krannitz - Canadian Wildlife Service, Originally published in THE WILSON BULLETIN, 113(4), 2001, pp. 441–444 We report on the incidence of male incubation and multiple brooding in Sagebrush Brewer’s Sparrows (Spizella breweri breweri) at the northwestern limit of their breeding range in southern British Columbia, 1998–2000, and in central Washington, 1996–1999. Males frequently incubated eggs, accounting for 28% of 329 observations of incubation by known individuals in British Columbia. In Washington, 51% of the males we monitored incubated eggs. Males and females appeared equally able to increase nest temperature. In British Columbia, 17% of females fledged two broods per season, and two females fledged three broods. In Washington, 5% of males fledged two broods per season. Only one previous case of male incubation has been reported in this species and multiple brooding has been poorly documented. These aspects of the breeding biology of other wellstudied species may be underestimated without the careful examination of populations of marked individuals.