ANTICOAGULANT EXPOSURE IN GOLDEN EAGLE (AQUILA CHRYSAETOS) POWER LINE ELECTROCUTION AND WIND TURBINE MORTALITIES.

ABSTRACT

Golden Eagles (Aquila chrysaetos) are susceptible to anthropogenic mortality factors, including toxic compounds in the environment such as anticoagulant rodenticides (AR) and sources of man-made energy. The physical and behavioral effects of some toxins may predispose eagles to certain causes of death (COD). To investigate the influence of ARs on mortality of Golden Eagles at wind turbine farms, we randomly tested liver samples from 31 eagles found dead on wind farms and submitted to the National Fish and Wildlife Forensic Laboratory from 2013-20. The comparison group was composed of 31 Golden Eagles sampled during the same time frame with a COD of power line electrocution as a proxy for a relatively lower effort and altitude activity. Associations between COD, AR exposure, sex, and life stage were assessed. In each group, 12 birds (35%) were found to have been exposed to brodifacoum or bromadiolone prior to death. Logistic regression showed no significant association between COD and sex (P=0.194) or life stage (P=0.895). Across both mortality types, life stage was not a significant predictor of AR exposure (P=0.725), but males were more likely to have been exposed to ARs (P=0.032). These findings suggest that there is no difference in the influence of anticoagulant exposure on higher and lower altitude activity in Golden Eagles.