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    Passive California Species May Fall Prey To Eastern Invader Snakes
    By News Staff | June 25th 2014 06:33 PM | 3 comments | Print | E-mail | Track Comments

    For people from eastern states like New York or Boston, California is a dream. People feel like they could just take over and declare themselves King and no one would try to stop them because it would hurt their feelings. It's like Canada, except the women are all in Daisy Duke shorts and bikini tops.

    But that passive demeanor isn't good when nature wants to kill you. And she does. Watersnakes, commonly seen in the lakes, rivers and streams of the eastern United States, are invading California waterways and may wipe out native species, according to a new 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. 




    This aggressive Southern watersnake will eat many different freshwater fish species, such as this Sunfish. It probably has a funny accent also. Credit: J.D. Willson/University of Arkansas

    "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.

    The common watersnake not only has the potential to spread through Central California, but also farther north to Oregon's Willamette Valley and to central Washington. The southern watersnake has a more restricted climatic niche but may spread through the Central Valley, where native fish and amphibians have already suffered significant declines. The two watersnake species also frequently interbreed, which could increase their invasiveness by producing hybrid genotypes able to tolerate a broader range of climates.


    "Watersnakes are not picky eaters," said co-author Brian Todd, a conservation biologist in the UC Davis Department of Wildlife, Fish and Conservation Biology. "With their predatory nature and generalist diets, our already imperiled native fish, amphibians and reptiles have much to lose should introduced watersnakes become more widespread."

    Nearly half of California's amphibians are considered Species of Special Concern or are listed under the state or federal Endangered Species Act, and more than 80 percent of the state's inland fishes are of conservation concern.



    Comments

    "Researchers suspect the nonvenomous snakes most likely were introduced by people "setting free" their pet snakes."

    If that isn't the biggest lie... water snakes are rarely kept as pets in the first place. This seems like laziness and regurgitating popular myths than it does actual informational content done by proper research. I'm willing to bet these hitch hiked there on some sort of product or what-have-you. But water snakes being released pets? What nonsense!
    I don't see these snake posing much of a threat to the environment and zero threat to people where they already subside. They are not dangerous to human life. In addition, native animals will likely keep their populations in check as king snakes, birds of prey and many other animals in California will prey upon them.

    This is just cheap journalism and insufficient research at its finest.

    Intriguing study! I'm with the authors--too bad nothing is currently being done about invasive herps BEFORE they've caused an ecological disaster in our already tenuous California systems.
    Interested parties should check out the killer full text here:
    http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0100277

    As an expert herper with over 30 years experience catching and monitoring snakes throughout California, I for one am thrilled to see this study. The threat of these invasive snakes outcompeting our native garter snakes is very concerning. It is great to see scientists finally trying to address the threat before there is too much damage! I just hope the State takes these results seriously!