REINTRODUCING THE WESTERN POND TURTLE TO YOSEMITE VALLEY.
Sidney M. Woodruff; National Park Service; PO Box 484, El Portal, CA, 95318; (256) 454-5967; sidmwoodruff@gmail.com; Ninette Daniele, Molly Thompson, Rob Grasso, Jessie Bushell, Rachel Mazur
Western pond turtles (Emys marmorata), a California species of special concern, disappeared from Yosemite Valley in Yosemite National Park in 1958. The most definitive causes for the disappearance in Yosemite Valley were likely from the deliberate introduction of the invasive American bullfrog in the 1950s, increases in mesocarnivore species from high food availability, and reductions in Western pond turtle habitat from past management actions. The Aquatic Wildlife program staff at Yosemite National Park have begun restoring Western pond turtles to the Valley through a head-start program with the San Francisco Zoo, starting the summer of 2016, to re-establish the species with a self-sustaining, breeding population. Determining turtle abundance and age/sex ratios through capture-mark-recapture methods will assist in understanding effective donor population sites and sizes to ensure sustainable populations for both the Valley and the existing donor sites. In the 2018 summer field season, we captured 495 Western pond turtles across 20 sites within Yosemite National Park and the Greater Yosemite area. Four experimental turtle individuals that were previously translocated to the Valley were tracked twice per month for condition and movement. With these combined efforts, an overall understanding will inform the next phase of the reintroduction for this imperiled species.
Poster Session