In the summer of 2011, visitors to the University of California, Davis, Arboretum may have witnessed an unusual site: small teams of students wielding large nets, leaping into the arboretum’s waterway to snag basking turtles.
The students weren’t in search of new pets — quite the opposite, in fact. The teams were part of a massive project to remove hundreds of invasive red-eared slider turtles from the arboretum in an effort to observe how California’s native western pond turtles fair in the absence of competitors.
Red-eared sliders are the most commonly traded pet turtles in the world, but are often released into the wild by disgruntled owners when they get too big to handle. Thanks to illegal dumping, the sliders, which are native to the Central United States and Northeastern Mexico, can now be found all over the world. Their new stomping grounds include California, where they vie for food and sunny basking sites with western pond turtles, whose populations are in rapid decline due to agriculture and urbanization.
The results of the removal study, published recently in the journal PeerJ, showed that western pond turtles get a lot fatter and healthier without competition from their invasive brethren — and the remaining sliders likely fair better, too. The study is the first to quantify competition between these two species in the wild.
Read more at University of California - Berkeley
Image: Turtles bask in the sun at Jewel Lake in Northern California's Tilden Regional Park. In the middle, a western pond turtle, one of California's few native turtles, holds up it's head, and on the far right sits an invasive red-eared slider turtle, which can be identified by the characteristic red stripe on the side of its head. (Credit: Photo by Robin Lopez)