Cooperative Fish and Wildlife Research Units Program: Idaho
Education, Research and Technical Assistance for Managing Our Natural Resources

Idaho Project

Cause of low nesting success and recruitment of Clark's and Western Grebes in Idaho

June 2017 - December 2023


Participating Agencies

  • US Geological Survey

Clark’s grebes are uncommon in North America and abundance has declined significantly over the past 50 years. Data from the North American Breeding Bird Survey (BBS) suggest 1.6% annual declines from 1966-2013 rangewide for Clark’s and western grebes (Sauer et al. 2014). Estimates for the number of western grebes (110,000) and Clark’s grebes (20,000) in North America are based partly on peak counts reported during the National Audubon Society’s Christmas Bird Counts (CBC) (Kushlan et al. 2000, 2002; National Audubon Society 2004). No comprehensive surveys of nesting sites have been conducted. Because of their rarity and their continued population declines, Clark’s grebes were included on a recent list of birds in North America that are most in need of conservation action (State of the Birds Watch List; Rosenberg et al. 2014). The western grebe is a candidate species for listing as threatened or endangered in Washington, and Clark’s grebes are a species of concern in Arizona, Montana and Wyoming (Ivey and Herziger, in Ivey 2004).

Research Publications Publication Date
Lachman, D. A., C. J. Conway, K. T. Vierling, and T. Matthews. 2020. Drones provide a better method to find nests and estimate nest survival for colonial waterbirds: a demonstration with western grebes. Wetlands Ecology and Management 28:837–845. doi: 10.1007/s11273-020-09743-y September 2020
Presentations Presentation Date
Yen, A., C.J. Conway, K.T. Vierling, D.A. Lachman, and T. Matthews. 2023. An inventory of Western and Clark’s grebe breeding lakes across North America. Graduate Student Fellows Showcase. Center for Digital Inquiry and Learning, University of Idaho. Moscow, ID. 27 Oct 2023. October 2023
Theses and Dissertations Publication Date
Yen, A. 2023. Western and Clark's Grebes: impacts of weather on nest fate and a range-wide summary of threats to breeding colonies. MS Thesis, University of Idaho, Moscow, ID. December 2023