Warming weather brings out one of New Jersey’s most misunderstood species
By: Michael Davenport, GIS Program Manager
I recently had the opportunity to accompany Kris Schantz, a biologist with the NJ Endangered and Nongame Species Program, to search for timber rattlesnakes (and northern copperheads) emerging from their dens in northern New Jersey.
Many New Jersey residents are surprised to learn that we have venomous snakes within our state, the most densely populated state in the U.S. We have two venomous species, in fact.
The timber rattlesnake is an Endangered species in New Jersey, while the northern copperhead has a status of Special Concern. To learn more about venomous snakes in New Jersey, please read my blog entry from May 13, 2011 and visit our online field guide:
Roads are a necessary component to human survival. Since New Jersey is such a densely populated state we have a lot of them. Many of them have a negative effect on wildlife. One of these impacts is how they block or impede the natural migration of amphibians and reptiles as they search for mates or expand their territories.
During the summer I am always a little more aware while driving. In the next week many terrapins will begin to emerge from coastal waters to find nest sites. Box turtles and other freshwater turtles are seeking mates and nest sites. Snakes often bask in roadways to help them thermoregulate. Last week while I was driving down one road in the Pinelands I saw two cars pass me in the opposite lane. After they sped by, on the shoulder, I noticed something odd but I knew exactly what it was. A tail was flinging crazily in the air. I thought it was a snake but was’t 100% sure so I stopped and turned around to check it out. It turns out it was a snake and it was an endangered timber rattlesnake. This is only the second timber rattler that I’ve ever seen in the wild and they are quite a rare occurrence. It was still alive but severely injured. I pulled it off the road before another car hit it. I called Dave Golden a zoologist with NJ Fish & Wildlife and took the snake home with hopes that it would survive long enough to be transferred to the Cape May County Zoo. Unfortunately, it died an hour after I got home. As you travel our many roads this summer please be aware of your surroundings and watch out for any snakes or turtles that enter the roadway.
Timber rattlesnakes are a very docile snake, however they are still venomous and you can die if bitten. If you encounter a rattlesnake do not attempt to pick it up!!! I was extremely cautious of this snake even though it was injured. Please call 1-877-WARN-DEP immediately if you encounter a timber rattlesnake that is near your home and/or if you or it are in any kind of danger. Record information about your sighting and report it to the Endangered & Nongame Species Program here.
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Having accurately mapped rare species data is essential for insuring that critical habitat for those species remains protected. For that reason, I recently accompanied Kris Schantz, a biologist from the NJ Endangered and Nongame Species Program, in documenting two timber rattlesnake den locations in northern New Jersey using a GPS (global positioning system) unit. Our goals were to see if the rattlesnakes had emerged from hibernation, survey how many were present, and to accurately map their locations in the heavily wooded area less than 30 miles outside New York City.
Timber rattlesnakes (Crotalus horridus horridus), like other reptiles, are cold-blooded. In order to survive through the long, cold winter in New Jersey, they hibernate in dens. Research has shown that rattlesnake dens in the northern part of the state can vary from rocky outcroppings with crevices, ledges or boulders to forest interior dens consisting of a few rocks and a hole in the ground. In New Jersey’s Pinelands, however, rattlesnake dens are quite different. Rattlesnake dens in the Pinelands are usually underground crevices near bodies of water, often underneath large tree roots.
Rattlesnakes will almost always use the same den year after year. In addition, rattlesnake young typically follow the scent trail of their mother in order to find their way to her den their first fall, or may follow any timber rattlesnake to a suitable den. As a result, a good den site may provide a winter refuge for a number of rattlesnakes of all age classes, as well as other species of snakes.
Since the goal of our mission was to map den locations, we had to make sure we arrived at the den site once it was warm enough for the rattlesnakes to come out of their crevasses to bask but before they had enough warm weather to travel away from the den site. Timing was crucial. After a week with some fairly warm days mixed with very cool nights and a few cool days, we ventured out during the last week of April on a day when the air temperature climbed into the lower 80’s.
The first den site we visited required a fairly long hike through a rocky, deciduous forest. Fortunately, Kris had visited both den sites several years earlier so she had a good idea of where we needed to go. We were fortunate to find two individuals at the den site, one yellow-phase juvenile and one yellow-phase sub-adult or young adult. While I GPSed the den site, Kris attempted to determine their sex based on their appearance (the young adult was a female but the juvenile’s sex could not be determined).
GPS units work when there is an unobstructed line of sight to four or more GPS satellites. With 7-8 satellites being detected by the GPS unit, my task of mapping the site was fairly easy and took little time. The trees had yet to leaf-out so my GPS unit had a clear signal from above. We also observed a northern black racer (Coluber constrictor constrictor) at the den site.
The second den site required a much longer and more strenuous hike accompanied by swarms of black flies. At that location, we observed three rattlesnakes – one black-phase adult (sex undetermined), one yellow-phase adult male, and one yellow-phase sub-adult or young adult (sex undetermined). GPSing this location took a little more effort though due to the terrain both because it was more difficult to get to the site and once there, the terrain made getting a clear signal on the GPS unit a little more tricky and it took far longer than at the first den.
Out of the five rattlesnakes we observed, only one ever rattled. Rattlesnakes rely on their camouflage as their first line of defense. Even when we were close by, they remained motionless. At no point did any of the snakes approach us or attempt to strike. The only two individuals which moved at all during our survey, moved away from us into rock crevasses and that was likely due to our prolonged presence staring at them.
Snakes, and venomous snakes in particular, have an undeserved bad reputation. At no point during our survey did I ever have any fear of being bitten by a rattlesnake. In all honesty, I was actually far more afraid of being bitten by a tick instead (I only found about four or five on me during the entire day).
