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Growth, population structure, and reproduction of western pond turtles (Actinemys marmorata) on the central coast of California

January 1, 2008

We studied the population structure and growth of western pond turtles (Actinemys marmorata) at Vandenberg Air Force Base along the coast of central California in April 1995 and June 1996. We captured 179 individuals (115 males, 27 females) from 7 ponds during 26 days of trapping. Many turtles were adult-sized, but based on scute annuli, 74% were < 10 years of age, including many 2- to 3-year-olds. This population structure likely was due to a relatively fast growth rate, especially compared with closely related aquatic turtles in eastern North America. Mean clutch size was 5.2, but 66.7% of females were gravid, and 1 female produced 2 clutches. These reproductive data are similar to those reported for other populations in the southern portion of the species' range. Females reached reproductive maturity as early as 4 years of age. The relatively mild temperatures of California's Mediterranean climate, especially when compared to the seasonal extremes in more continental and northern regions of North America, may explain the different growth rates and population characteristics of freshwater turtles from these 2 regions of North America. ?? 2008 Chelonian Research Foundation.

Publication Year 2008
Title Growth, population structure, and reproduction of western pond turtles (Actinemys marmorata) on the central coast of California
DOI 10.2744/CCB-0705.1
Authors D.J. Germano, G. B. Rathbun
Publication Type Article
Publication Subtype Journal Article
Series Title Chelonian Conservation and Biology
Index ID 70033135
Record Source USGS Publications Warehouse
USGS Organization Forest and Rangeland Ecosystem Science Center