Martell, M., P.T. Redig., J. Nibe, and G. Buhl. 1990. Survival of released rehabilitation bald eagles. Final report submitted to the Minnesota Department of Natural Resources. 73 pp.
The rehabilitation and release of injured wildlife has become a widespread occurrence over much of North America with over 2500 permitted wildlife rehabilitators in the United States. While exact figures are not available it can be assumed that many of these permitees handle birds of prey. One of the underlying assumptions of raptor rehabilitation is that a released bird survives and resumes "normal" activities. Most importantly, it is assumed, these birds become part of the breeding population, thus contributing to the conservation of their species.
Unfortunately, very little effort has been made to document the survival, or breeding rates, of released rehabilitated raptors. This information is critical when assessing the value of rehabilitation to the conservation of populations. Duek, et al. (1981) documented nesting by 2 released rehabilitated Bald Eagles (Haliaeetus leucocephalus) 1 and 2 years respectively after their release. They also reported on band returns and incidental sightings of other raptors released from the University of Minnesota. Servheen and English (1979), reported on the movements of color-marked rehabilitated Bald Eagles in the Pacific Northwest. Radiotelemetry was used by Hamilton et al. (1988) to monitor the survival of eight Red-tailed Hawks (Buteo jamacensis) and one Red-shouldered Hawk (Buteo lineatus) in Louisiana.
Our study was designed to monitor the survival, movements, and breeding attempts of Bald Eagles released from The Raptor Center at the University of Minnesota (TRC). Since 1974 TRC has treated over 630 Bald Eagles for a variety of ailments including fractures, soft tissue injuries, poisoning, and disease. Over 50% of the eagles admitted to the Center have been released to the wild.