Survival of Montana Golden Eagles (Aquila chrysaetos)

ABSTRACT We monitored 25 Golden Eagles in Montana, USA, from 2011 to 2015 over 3,601 days using tail-mounted satellite transmitters. Using the best available direct observation and circumstantial evidence, we surmise that only a single eagle (adult female floater) died during monitoring, resulting in a daily survival estimate of 0.9997 (SE = 0.0003) and an annual survival estimate of 0.905 (SE = 0.0907) for a mixture of adult and younger, resident and migrant, breeder and nonbreeder eagles of both genders living in relatively undisturbed regions of the western United States. Under this scenario, adult daily survival averaged 0.9996 (SE = 0.0004) and adult annual survival averaged 0.858 (SE = 0.132).