Author ORCID Identifier

https://orcid.org/0009-0002-6317-6479

Semester

Fall

Date of Graduation

2025

Document Type

Thesis

Degree Type

MS

College

Davis College of Agriculture, Natural Resources and Design

Department

Wildlife and Fisheries Resources

Committee Chair

Laura Gigliotti

Committee Co-Chair

Holly Morris

Committee Member

Christopher Rota

Abstract

Wildlife reintroductions function to regain wildlife populations in areas where they have been extirpated or greatly diminished. One such species that has been reintroduced to several states is the North American river otter (Lontra canadensis). The West Virginia Division of Natural Resources (WVDNR) conducted a river otter reintroduction effort between 1984-1997, releasing 245 individuals into the state. The reintroduction was deemed a success with the WVDNR opening a regulated trapping season for river otters in 2011, allowing trappers to take one river otter per season. As the population has reestablished in West Virginia, several management challenges have arisen including interest in increasing the trapping bag limit, and human-wildlife conflict that has occurred surrounding fish stocking in the state. In chapter 1, I evaluated current and future management options for otters by calculating annual survival, fecundity, and modeling population growth rates for the next 20 years. To calculate river otter survival, we captured 36 river otters and equipped them with internal very high frequency transmitters (VHF) and monitored them from September 2023-May 2025. Breeding season was found to have a negative effect on survival resulting in an annual survival rate of 0.79 (95% CI =0.65-0.93). I modeled population growth by combining survival estimates with reproductive data obtained from reproductive tracts of female river otters (n=134) collected by the WVDNR from 1993 to 2024. I incorporated known harvest from 2011-2025 and conducted population projections into the future with various harvest scenarios (bag limit of 1, 2, 3). These results indicated that harvest scenarios of 1 and 2 otter per year resulted in positive population growth rates; however, there is uncertainty in incorporating a 3-otter limit as a portion of the simulations resulted in extinction events. In chapter 2, I addressed the human-wildlife conflict focused on otters and fish stocking, particularly trout. Wildlife species have been observed using human-subsidized food resources in other systems; however, fine-scale assessments of river otter space use in relation to stocked fish has yet to be evaluated. We attached global positioning systems (GPS) transmitters to 27 otters, resulting in 24 spatial datasets. From those spatial datasets, I calculated home range size, movement rates, and resource selection related to both trout stocking and environmental features. Both stocking and breeding status affected the size of home ranges. Home ranges were larger during the stocking period (99.47 km2, 85% CI: 72.73-126.20) compared to the non-stocking period (19.41 km2, 85% CI: 0-40.81). This indicates that otters are not localizing on stocked areas and could point to the relevance of other covariates or factors not included in this analysis. Home ranges were larger during the breeding season (82.91 km2, 85% CI: 59.96-105.85) compared to the nonbreeding season (8.91 km2, 85% CI: 59.96-105.85. Movement rates were affected by breeding, but not by stocking. Movement rates were higher during the breeding season (398.53 m/hour; 85% CI: 334.73 - 462.34) compared to the non-breeding season (206.05 m/hour; 85% CI: 136.81 - 275.29). River otters selected locations near water, stocking, and roads, and selected for wetlands over other habitat types. Collectively, the results of this research will provide valuable information for informing future management decisions for otters in West Virginia.

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