Reintroduced Grey Crowned Cranes (Balearica regulorum) Exhibit Reduced Dispersal and Smaller Home Ranges than Wild Conspecifics in Rwanda

Reintroductions are essential in wildlife conservation, but their success depends not only on demographic outcomes such as survival and reproduction, but also on behavioral adjustments that determine integration into the wild. The Grey Crowned Crane (<i>Balearica regulorum</i>), an endangered species, has suffered dramatic declines due to habitat loss, disturbance, and illegal capture. In Rwanda, a large-scale amnesty rescued 242 cranes from captivity, with 166 rehabilitated and released into Akagera National Park. This study used GPS-GSM telemetry to investigate post-release movement of reintroduced captive-rescued cranes in comparison with wild individuals. Twenty-one cranes (10 reintroduced, 11 wild) were tracked for 5-1118 days, with 15 individuals meeting criteria for detailed analyses. Reintroduced cranes exhibited reduced dispersal, with only 2 of 7 dispersing compared to 7 of 9 wild cranes, and typically after much longer residence at the release site. Reintroduced cranes also had smaller maximum displacements (median 8.4 km) and smaller home ranges (median 3.3 km²) relative to those of wild cranes (median 24.0 km and median 22.6 km², respectively). These findings suggest that supplemental feeding and extended captivity (2 days to 10 years) of reintroduced cranes strongly influenced their high site fidelity and movement patterns. While limited dispersal may benefit short-term survival, long-term monitoring of survival, reproduction, and demographic trends is critical for assessing whether reintroduction achieves population recovery.