Maintenance of stable water levels during the nesting season is critical for successful reproduction in Aechmophorus grebes. Western and Clark?s grebes build floating nests that are vulnerable to water level fluctuations and drawdowns, which can cause nest failures. Measures to promote successful grebe reproduction may help offset declines of these birds due to habitat loss, human disturbance at breeding colonies, and environmental contaminants. During this three-year study we developed the first successful artificial grebe nest platforms designed for fluctuating water levels at an inundated, former quarry site that is now used for recreational purposes and aquifer recharge. During the summer months of the nesting season the surface elevation of the lake drops 6.1 meters. Placement of these nest platforms resulted in utilization and nest success rates of 78% and 73%, respectively. Over three years a total of 31 young were produced, resulting in a brood count ratio of 1.41 chicks per adult. Education and cooperation are needed to limit water level fluctuations during the grebe nesting period, but if this is not practical then these artificial platforms may be an appropriate alternative for enhancing grebe production, and may benefit other over-water nesting birds.
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