Survival and post-release movements of river otters translocated to Western New York

Survival and post-release movements of individuals translocated for reintroduction purposes have implications for intra-specific interactions, which are essential for reproduction, and, ultimately, for the success of the reintroduction effort. Between 1997-1998, 28 (14M:14F) Lontra canadensis (river otters) were translocated to the Genesee River, NY, to restore extirpated populations. Otters were implanted with transmitters to determine survival, cause of mortality, and post-release movements. Five (3M:2F) otters died during the study: three (2M:1F) mortalities were caused by collisions with vehicles and two (IM:IF) were from unknown causes. Survival rate during the first year was 0.89 (95% CI = 0.78-1.00); annual survival rate was 0.92 (95% CI = 0.79-1.00) and 0.86 (95% CI = 0.70-1.00) for males and females, respectively. Post-release dispersal distance of 22 (HM:HF) otters ranged from 1.2 to 54.0 km (mean = 12.5 km, 95% CI = 8.5-23.7 km). Dispersal distance of females was greater than that of males by a mean of 8.7 km (95% CI = 0.1-19.2 km). River otters that dispersed >15 km from the release site experienced higher mortality.