Snakes in the pond

Asked April 28, 2016, 1:58 AM EDT

How do Cotton Mouth Water Moccasins get into a private pond? They don't just fall out of the sky.

I have been around that pond for 30 yrs, and never saw a snake.

Macon County Illinois

4 Responses

Thank you for your question. Without seeing the snake, I can't say for sure what species it is, but according to the Illinois Natural History Survey, the cottonmouth (Agkistrodon piscivorus) occurs in just a few counties in the extreme southern part of Illinois, well south of Macon County (see: http://wwx.inhs.illinois.edu/collections/herps/data/ilspecies/ag_piscivo/). That's not to say you didn't see one. Someone could have released a captive snake near the pond, for example. Barring someone releasing a cottonmouth, I suspect the species you saw was most likely the northern watersnake (Nerodia sipedon). It is widely distributed across Illinois. It is non-venomous. It is often mistaken for the cottonmouth, because older snakes of this species often become very dark, and their pattern becomes obscured.
As far as how did it come to be in the pond, watersnakes are often found crossing roads quite some distance from waterbodies. This snake may have simply left its former home and came upon your pond and decided to stay.

Hope this answers your question, and thanks for using Ask an Expert.

Jim

Thank you so much for your response. I should have pointed out that the pond was my Uncles and was in Brown County. It is now drained. Thanks again. Sandi

Also, I never saw the snakes. I just took the uncles word for it. I did see a whole lot of giant Bullfrogs!

Thanks for the additional information. Brown County is also well out of the range of the cottonmouth in Illinois. Snakes are difficult to see because, unless they're crossing a road or your sidewalk, they blend in so well with their natural surroundings. Also watersnakes are usually in or close to the water, and, if they detect any threat at all, immediately get under water to avoid detection.

Thanks again for using Ask an Expert.

Jim