Climate change is causing changes in weather patterns and has led to prolonged droughts. Much of western North America has experienced recent droughts, especially in California, which experienced a historic drought from 2012–2016. Drought can significantly impact aquatic turtles, especially those populations existing in ephemeral habitats. Much of the range of western pond turtles (Actinemys) has been subject to recent droughts. In 2017, after the worst of the drought had passed, I sampled a large population of Actinemys along the southern flank of the Tehachapi Mountains, California, which I first trapped in 2007 and 2010. I trapped the small pond in four of seven years between 2017 and 2023 when there was much less water than before. I caught only 15% (48/321) of the number of turtles I caught before the drought, but there were adult turtles that survived from earlier trapping, unmarked adults that were alive in 2010, young turtles, and many reproductive females. Growth rates were lower than previously, but growth rates were increasing in the last 2 years of trapping. Survivorship in 2017–2023 was similar to that in 2007/2010. Unlike many small ponds in the range of Actinemys that are ephemeral, relying on water input from the surrounding watershed, the study pond is spring-fed. Intermittent years of high rainfall (>500 mm) likely have recharged the surrounding aquifer that keep this pond with some water even in drought years, allowing the population of Actinemys at Gorman Pond to survive an extended drought period.
David J. Germano (Fri,) studied this question.