Oral Presentation- Symposium 12th International Mammalogical Congress

Pictures, predators, and prey: Camera data and community dynamics after a fisher reintroduction (#133)

Roger A Powell 1 , Aaron N Facka 2
  1. Department of Applied Ecology, North Carolina State University, Raleigh, NC, United States
  2. Oregon State University, Portland, OR, United States

Researchers are often concerned with how reintroduced organisms fare in their new environments, but often cannot document how the reintroduced organisms affect their new communities. Fishers (Pekania pennanti) are a model mammalian carnivore that has been translocated > 40 times across its range in North America. Fishers are specialist predators on porcupines (Erethizon dorsatum) in localities where they co-occur and may regulate their populations. Otherwise, they are generalists that consume, and affect, many types of medium­­‑ to small‑sized mammals. Understanding how predators forage for and change the abundance and distribution of prey is important to manage and conserve them into the future. Subsequent to the reintroduction of 40 fishers over 3 years (2009-2012) to their former range in northern California, USA, we placed trail cameras at over 600 locations (yearly = 100 ± 41) for reasons including to estimate fisher reproduction and evaluate the spatial distribution of fishers through time. We deployed both baited and un-baited cameras for an average of 42.4 ± 33-52, distributed across years and seasons. We quantified the distributions and naïve occupancy rates of key prey species through time. The naïve occupancy rates of tree squirrels were highest for Tamiasciurus douglasii (0.53 ± 0.16), Sciurus griseus (0.41 ± 0.14;), and Glaucomy sabrinus (0.08 ± 0.06) but were highly variable in time and space indicating fishers were not negatively affecting them after release.  We will further evaluate specific habitat metrics for each of these species to evaluate how these overlap with habitat and prey selection by fishers.