This species of watersnake is potentially invasive and, through predation, could contribute to continued population declines of endangered or threatened fish and frogs in that state.
(PRWEB) June 01, 2016
Herpetologica – Few aquatic species have the ability move independently from native to foreign waters. Human activities, however, are often responsible for the establishment of aquatic and semi-aquatic species in water bodies well outside of their native ranges. A population established in non-native waters can provide important baseline data to predict the future impacts of the exotic species spreading to other suitable habitats outside its native distribution.
Southern Watersnakes are native to the southeastern portions of the U.S., but they have been found in two areas in California. This species of watersnake is potentially invasive and, through predation, could contribute to continued population declines of endangered or threatened fish and frogs in that state.
An article published in the current issue of the journal Herpetologica examines the life-history characteristics of Southern Watersnakes inhabiting a single lake in Harbor City, California. The researchers captured more than 300 specimens over about two years, and quantified the physical characteristics, diet, and reproductive capabilities of the snakes. Intensive efforts to trap and remove the snakes seemed to have little effect on the overall population. The authors of the study reported that each adult female watersnake gives birth to an average of 21, and up to 46, offspring every two years, making it potentially difficult to eradicate the population.
The researchers noted that capturing and removing the largest female specimens might be key to eliminating this non-native population. The isolation of the lake makes the snakes seem exotic rather than invasive—but only in that location. If human activities introduced Southern Watersnakes into other water bodies in California, other native species could be at risk.
Full text of the article “Ecology and Control of an Introduced Population of Southern Watersnakes (Nerodia fasciata) in Southern California,” Herpetologica, Vol. 72, No. 2, 2016, is now available.
Herpetologica is a quarterly journal of The Herpetologists’ League, containing original research articles on the biology of amphibians and reptiles. The journal serves herpetologists, biologists, ecologists, conservationists, researchers, and others interested in furthering knowledge of the biology of amphibians and reptiles. To learn more about the society, please visit: http://www.herpetologistsleague.org.