Game Bird Carcasses Are Less Persistent Than Raptor Carcasses, But Can Predict Raptor Persistence Dynamics

Post-construction fatality monitoring (PCFM) is an important tool to understand wind energy impacts to eagles, and accurately estimating the rate of fatalities at an operating wind facility requires that researchers account for sources of imperfect carcass detection: observer efficiency and carcass persistence. Because eagles and other large raptors are difficult to obtain for carcass persistence trials (CPTs), estimates of carcass persistence often rely on trials that use game birds as surrogates. However, game birds consistently have shorter persistence times than large raptor carcasses, which can ultimately lead to an overestimation of eagle fatalities. Accounting for this bias in fatality rates benefits wind companies, wildlife agencies, and other stakeholders by increasing the likelihood that mitigation measures match the true level of take.