Since the West Virginia river otter reintroduction in the 1980s and 90s, river otters have expanded across the state. In order to better understand the success of the reintroduction, managers at West Virginia Division of Natural Resources (WVDNR) wanted to better understand the survival and population dynamics of river otters, which in turn can help managers in setting hunting/trapping seasons and limits.
We captured 36 river otters, implanted VHF transmitters and attached ear tags, and monitored the otters for survival. Six mortalities were recorded: one poaching incident, 2 roadkill, and 3 unknown causes of death. No trapper-harvested mortalities were recorded. Otter annual survival was approximately 79%. Fecundity data was compiled from 134 female otter reproductive tracts collected from 1993-2024. This analysis determined pregnancy rates of 49% for yearlings and 66% for adults as well as mean litter size of 2.295. Using this survival and fecundity data, population growth rates were modeled with a 1, 2 and 3-otter bag limit incorporating estimated average trapper take and maximum trapper take. Based on modeling these scenarios, a 2-otter bag limit provides an increase in trapping opportunity without risk of extirpating otter populations in localized streams, watersheds, or counties.