© J.D. Willson/University of Arkansas
Southern watersnakes commonly eat mole salamanders, a group that includes two endangered species in California. A UC Davis study finds that the non-native snakes are invading California waters, posing a threat to native fish, amphibians and reptiles.
Waters nakes, commonly seen in the lakes, rivers and streams of the eastern United States, are invading California waterways and may pose a threat to native and endangered species in the state, according to a University of California, Davis, study.
While scientists do not know exactly how many watersnakes are in California, roughly 300 individuals of two different species - the common watersnake and the southern watersnake - have been found in the Sacramento area (Roseville and Folsom), and at least 150 were seen in Long Beach. Researchers suspect the nonvenomous snakes most likely were introduced by people "setting free" their pet snakes.
"The issue is not yet out of control," said lead author Jonathan Rose, a doctoral candidate in the UC Davis Graduate Group in Ecology. "However, we recommend that action be taken now to control emergent populations of these non-native snakes while they remain somewhat restricted in California. Waiting until they become entrenched could cost more ecologically and economically."
The study, published today in the journal
PLOS ONE, identified areas that would be climatically suitable for the watersnakes should their populations continue to increase. It found that potential distributions of watersnakes overlap with the giant gartersnake and the California tiger salamander - both on the federal list of threatened species - as well as the foothill yellow-legged frog, an amphibian of conservation concern. These native species can become prey or a competing species for the invasive watersnakes.
