Island Dispatch | April 2016

Leonard Jones, a PhD Candidate at the University of Washington, is using genetic data from three species of garter snakes (Thamnophis sp.) to determine how different island populations vary genetically. This data will reveal how much these snakes move between the islands and breed, and which snakes from the mainland are most closely related (and therefore represent the likely population source for our island snakes).

While Leonard searches the ground for snakes on our Sundstrom and Red Mill Farm Preserves, Rochelle Kelly scans the skies for bats. Over the course of the last two years, Kelly, who is also a PhD candidate at the UW, has focused on clarifying the distribution of, and differences between, bat species and how they may be influenced by the isolation of these islands. Last summer, Kelly captured between two and seven species per island, collecting DNA and fecal samples before releasing them. Of particular note was Kelly’s discovery on our Vendovi Island Preserve of exclusively bachelor colonies of California and Yuma myotis (small brown bats). While the male-only population remains a mystery to be further explored, Kelly’s findings suggest that even small and remote islands provide valuable habitat for bats.

The “Shaw Island Townsend’s vole” (Microtus townsendii pugeti) is considered a “Species of Greatest Conservation Need” by the Washington Department of Fish & Wildlife (WDFW). Though named for Shaw Island, this Townsend’s vole is known to inhabit 16 islands in our archipelago. WDFW biologist Ruth Milner is investigating this species’ distribution and genetic relationship with the mainland’s Townsend’s voles, conducting some of her work on SJPT’s Peach Preserve on Guemes Island. Her research will help WDFW prioritize conservation actions and understand how small mammals on individual islands may be related.

While the work of these scientists furthers their own academic disciplines, it also helps us gain a deeper understanding of the animals that live on San Juan Preservation Trust properties. By learning who is occupying these landscapes, we can better craft our management plans to ensure quality of habitat that these species need to flourish.
***
WANTED: YOUR ROAD AND CAT KILLS! You can contribute to these scientists’ research by saving dead voles and snakes found in the San Juan Islands. If the specimen is still fresh and intact, it should be placed in a ziplock bag and frozen. Please provide information on date of collection and either a precise address or GPS coordinates where found. Voles can be sent to Ruth Milner, WDFW (email Ruth.Milner@dfw.wa.gov to coordinate delivery). Contact Leonard Jones (lnj204@uw.edu) with specimens of any snake.