Survival of adult reddish egrets Egretta rufescens marked with satellite transmitters

Abstract

The reddish egret Egretta rufescens is the rarest heron in North America, and there are many information gaps in our understanding of its ecology. The population size of the reddish egret is relatively small, and although its range spans from the Gulf Coast of the United States to the northern coast of South America, it is restricted to shallow, coastal lagoon systems. Nest survival and juvenile survival have been examined in the reddish egret; however, adult survival has not. We marked 30 adult reddish egrets with satellite transmitters and used the known-fate model in Program MARK to estimate monthly survival. Monthly survival estimates were high and best explained by season, with a 0.992 (95% CI: 0.974-0.997) survival rate during the breeding season and 0.949 (95% CI: 0.912-0.971) during the nonbreeding season. This is the first study to estimate adult survival of reddish egrets, and it provides new information on the ecology of the species.