By Caroline Sheldon
Due to excessive trapping in the early 1900s, Martes pennanti (Fisher) populations experienced a significant decline in New York State, but thanks to trapping regulations and reintroduction efforts, populations are now thriving (Baginski et al., 2015). However, in the Northwest United States, Fisher populations are declining due to habitat destruction and fragmentation because Fishers reside in a specific range of habitat conditions (Baginski et al., 2015).
Currently, Fisher populations are monitored using camera traps and reports from the public, but these methods are not always a reliable source. The use of environmental DNA (eDNA) is a relatively new method of detection that uses trace DNA released from organisms into soil or water in the surrounding environment (Bohmann et al., 2014). We are working on the development of an eDNA assay for Fishers as a way to non-invasively detect the elusive species. By using eDNA as a detection method we will be able to gather information about the occupancy and changes in relative abundance of Fishers, however, there are some challenges that come from using eDNA extracted from water samples when trying to detect a terrestrial mammal. Since Fishers are a terrestrial animal they spend little time in, or around water which lowers the chances of finding eDNA, and any eDNA that is found may be old and degraded. Once the eDNA assay is developed, we will be analyzing water samples from primary streams and vernal pools around the SUNY Oswego Rice Creek Field Station in order to test for the presence of Fishers, as well as study the environmental conditions (e.g., sampling timing) under which the detection rates are highest. The ultimate goal of this project is to successfully create an eDNA assay for the Fisher that can be used as another source of detection, particularly when the species is rare (i.e., on the edge of its range expansion or in the Pacific Northwest where it is threatened).
Citations:
New York State Department of Environmental Conservation (NYSDEC). 2015. New York State Fisher Management Plan. Albany, NY.
Kristine Bohmann, Alice Evans, M. Thomas P. Gilbert, Gary R. Carvalho, Simon Creer, Michael Knapp, Douglas w. Yu, & Mark de Bruyn. (2014). Environmental DNA for wildlife biology and biodiversity monitoring. Trends in Ecology & Evolution, 29(6), 358–365.
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