Historic translocations impact current fisher populations
In many cases, we still know very little about the success of past efforts to move animals for conservation, or “translocation”. Tracking animals over time is essential to understand whether translocations can effectively restore populations. Genetics offers a cost-effective way to monitor translocated animals. By using non-invasive samples like hair and scat, scientists can identify individual animals, track their survival, and see how they move and reproduce over time.
In a recent study, Rocky Mountain Research Station scientists and state agency partners looked at over 30 years of genetic data from where 315 fishers—an at risk, forest-dwelling carnivore—were released into federal, state and private forests in Idaho and Montana. These translocations took place over the last 100 years using animals from different regions to help boost local populations.
The scientists found two main genetic clusters of fishers. In the Cabinet Mountains, fishers were closely related to animals originally translocated from the midwestern U.S., the source population from which they were derived. In contrast, fishers in Idaho and Montana outside of the Cabinet Mountains were more closely related to animals from both British Columbia and remnants of a local U.S. northern rocky mountain fisher population. Interestingly, these two genetic clusters have remained separate over time, with limited signs of movement or interbreeding even decades after translocation. Additionally, the scientists found that a few animals had mixed ancestry, including some with recent British Columbia ancestry—suggesting that past translocations from British Columbia may have worked better than previously believed.
Overall, this research suggests that translocations did help establish new populations that survived, but fishers mostly stayed near where they were released. That means that while translocations created new populations, they didn’t necessarily help expand the geographic range of the species. This study highlights why it is critical to monitor translocations over time. Long-term monitoring of translocations using genetics helps us understand their effectiveness in conservation so we can make management decisions to recover declining species in the future.