Cause of low nesting success and recruitment of Clark's and Western Grebes in Idaho
June 2017 - December 2019
- 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).