Natural History: Cottonmouth

On Thursday March 12, 2015 we went on our first class field-trip to Caw Caw County Park. As we were walking over the small bridge that led us to our second location of traps we were lucky enough to see two larger Cottonmouth snakes (Agkistrodon piscivorus) as well as one smaller cottonmouth. Later in the field trip, after we collected our second batch of traps, several students went back to where we had original seen the three snakes and saw a fourth cottonmouth. The smaller cottonmouth was very close to where we were walking in the wet grass beneath the boardwalk which made the snake very visible and easy to observe, from a safe distance of course, considering these snakes are venomous. 

The picture of the snake I took shows a dark brown coloration, although there is a wide range of patterns and colors observed within this species. Although the snake pictured was smaller than the other two observed I believe it is still an adult because adult cottonmouths are usually dark and solid colored whereas juveniles tend to be more brightly patterned with a yellow tip on their tail. The smaller adult cottonmouth could have possibly been a female since it was smaller than the other two and males are larger than females in this species of snake, but this is only an educated guess as I did not get a close enough look to confirm. The head of the snake was large and triangular and had a facial pit. You could see the keeled scales on the snakes body as well. Their facial pit is a characteristic that defines them as “pitvipers” under Family Crotalidae.

At first it was hard to spot the snakes in their habitat. They were well camouflaged within the brush and water (as you can see in the picture posted above). The snakes were out of the water at the time we observed them but they were all within close distance to get back in the water. This one in particular was laying on top of the tan grass. This makes sense for this species because cottonmouths are semi-aquatic snakes.

While at our first site on the field trip I was hoping to find and identify a non-venomous snake. I was prepared with my snake hook in case we were lucky enough to spot one. Unfortunately we did not see any at the first site and we did not find any non-venomous snakes at the second site either, but I was excited to get to observe these snakes from the boardwalk. Hopefully we get to see more snakes and other herps in their natural habitat on the upcoming trips!