| The western pond turtle (Actinemys marmorata) has been declining throughout its range due to a number of stressors including: habitat degradation and loss, exotic competitors, non-native predators, and epidemic disease. Our only native California turtle is listed as a California Species of Special Concern and a candidate species for listing under the federal Endangered Species Act. Few studies have examined the ecology of populations in lentic environments subject to livestock grazing. From 2011 through 2015, staff and volunteers tracked visually and/or using radio-telemetry devices, the seasonal movement patterns, habitat use and nest site selection of western pond turtles in eastern Contra Costa County, California. Preliminary statistical analyses of this multiple-year database are showing that male and female western pond turtles use the pond environment differently; however, they overwinter in the same relative location. Gravid females on average move 24.4 m. (±17.5 m.) away from the ponds, nest on south-facing slopes (mean aspect of 134± 31.9 degrees) with mean residual dry matter (RDM) levels of 1345 (lbs./acre)(1510 kg/ha), and vegetation heights ranging between 26.6 and 39.5 cm. These research findings show how western pond turtles utilize their pond and upland environment have significant conservation and management implications for rangelands. |