Restoring ecosystems requires an understanding of historical conditions. Islands are some of the most impacted ecosystems on the planet, and island restoration initiatives are now commonplace. Such programs, however, must be based on accurate assessments of historical community composition in order to establish appropriate restoration targets. I use phylogenetics, demographic analyses, and stable isotopes to reconstruct historical communities.
Releasing the 2nd marten captured on Isle Royale since 1917. After presumed extinction, martens are making a comeback. March 2018.
American martens are one of the most mysterious Isle Royale residents. Historically common, martens disappeared from the island by 1920, only to be rediscovered over 75 years later. Using a combination of genetic and demographic approaches, I found that extant Isle Royale martens were historically extirpated and recolonized Isle Royale from nearby Ontario, Canada in the late 20th century (Manlick et al. 2018, Fig. 1). We have also extended this work to show that Isle Royale red foxes are likely the product of intentional introductions for fur farming (Black et al. Submitted), and we reclassified a subspecies of Isle Royale red squirrel by showing they are not distinct from mainland populations (Savage et al. 2019). Collectively, this work illustrates widespread human impacts in a putatively pristine ecosystem, and questions the dogma of isolation that has directed the management of Isle Royale for nearly a century. Beyond Isle Royale, I have used these techniques to disentangle the similarly complicated history of martens in Southeast Alaska where species introductions have led to the uncertain management of this umbrella species (Pauli et al. 2015).
Figure 1. Reconstructing the colonization history of martens on Isle Royale (a) Potential source populations, the source of historical reintroductions (solid lines), and the potential translocation of martens to Isle Royale in 1966 (dashed line). Factorial correspondence analysis of microsatellite loci identified several genetic clusters, including Isle Royale (b). Fine scale structure revealed that Isle Royale is distinct from Michigan and Ontario martens, but suggest extant Isle Royale martens colonized from nearby Ontario (c).