Western pond turtles (Actinemys marmorata) are found along the western coast of North America, and in California, they are the only native species of freshwater turtle. The western pond turtle faces an increasing amount of pressure from habitat loss due to the urban and agricultural development of wetland ecosystems. Loss of habitat and devastating drought, in combination with competition between invasive species, has reduced the population of the western pond turtles, and they are now listed by the California Department of Fish and Wildlife as a species of concern. Our observational study is monitoring the health and recruitment of western pond turtles in an urban environment. We are monitoring turtle nesting sites, determining if they are forced to cross bike trails and roads to reach suitable habitat, and what impacts invasive species have on their population. We have questions regarding recruitment, and if the population of western pond turtles is successfully breeding. The bi-weekly turtle monitoring program was started in February 2017.
Our western pond turtle research results indicate a large population of A. marmorata occurs at Bushy Lake, as well as invasive red-eared sliders (Trachemys scripta elegans). As many as 51 turtles were observed at the site at one time. The invasive red-eared sliders comprised approximately 10% of the observed turtle populations. A. marmorata are known to have high site fidelity and have been observed to occur in the same area for as long as 30 years. It appears that there is a lack of recruitment of young turtles into the population, and very few immature or hatching turtles were seen during monitoring. Future research informed by the observational studies includes a competition study between A. marmorata and T. scripta elegans to determine impacts on populations and inform management options. Methods planned for future study include the following: 1) mark and recapture of turtles; 2) continued observation for nesting sites and recruitment of young; 3) telemetry studies and 4) a head-starting program to breed and release young turtles. We plan to continue our restoration efforts, working with local and state wildlife management professionals, with the goal of a healthy and thriving A. marmorata in an urban environment.