Survival of White-tailed Eagles Tracked After Rehabilitation and Release

Abstract

ABSTRACT There are many raptor rehabilitation centers around the world that receive and care for wild raptors. Wildlife rehabilitation is a labor- and cost-intensive part of addressing animal welfare. Apart from the compassionate aspect of taking responsibility for an injured animal, there remains an open question as to whether doing so contributes to animal conservation. The fates of such animals after their rehabilitation and release have rarely been studied. Long-term post-release monitoring is needed to assess survival and reproduction. Here, we investigate the post-release fates of 22 White-tailed Eagles (Haliaeetus albicilla), including juveniles, immature birds, and adults in Austria, the Czech Republic, Germany, and Slovakia. Using GPS tracking, we monitored the eagles for 2–2639 d (median = 340 d) between 2005 and 2023. The longest-surviving eagle was tracked for more than 7 yr. Release was followed by a short 6-d period of high mortality, followed in turn by a long-term annual adult survival rate of 74.6%. Anthropogenic factors contributed to 70% of the long-term mortality cases. Reason for admission, length of hospital stay, and use of flight aviaries had no statistically significant effect on long-term survival. Five eagles successfully bred and produced a total of 10 fledglings. Traveling as much as 1378 km, the released eagles dispersed throughout central, northern, and eastern Europe. Thus, it can be concluded that successful rehabilitation of White-tailed Eagles resulted in high survival rates; and in five cases, successful reproduction indicated effective reintegration into the wild population.