AUTHORS: Callie Klatt Golba, Peggy Notebaert Nature Museum of the Chicago Academy of Sciences; Gary Glowacki, Lake County Forest Preserve District; Kathryn McCabe, Lake County Forest Preserve District; Richard King, Northern Illinois University
ABSTRACT: Reintroduction is a tool used in conservation biology to establish a new population of previously extirpated species. It is often necessary when habitat fragmentation prevents natural reestablishment. In freshwater turtle species, reintroduction is becoming more common, but due to their longevity, continued monitoring and adaptive management is necessary to properly assess success. From 2020 to 2022, 175 headstarted Blanding’s Turtles were reintroduced at a recently restored site in Lake County, Illinois. The plan was to continue releases to meet or exceed an adult population size indicative of resiliency (Adult N ≥ 50) and maximize genetic diversity. Follow-up monitoring revealed lower than expected survival due to high predation. Releases were halted after detection of a shell rot fungus among captives in 2022. To determine the best strategy going forward, we used population viability analysis to compare release scenarios that differed in the age at release (direct release of hatchlings, 1st year headstarts, 2nd year headstarts), the number released, and the implementation of predator removal. Releases of older headstarts with concurrent predator removal were projected to result in the largest population size. Increasing number of egg donors resulted in relatively small effects on allelic richness, genetic diversity, and inbreeding. Results from the initial years of an experimental reintroduced population demonstrate the utility of continued monitoring to guide adaptive management in wildlife conservation.
