Warren County Wildlife: Timber rattlesnake is endangered in New Jersey

John Parke By John Parke The Warren Reporter
on May 08, 2013 at 1:19 PM, updated March 16, 2014 at 5:08 PM
"Rattlesnakes have the most highly developed venom system of all snakes."

When you think of rattlesnakes doesn't the image of one coiled next to a cactus out in the desert like that in an old Hollywood Western come to mind? Bet you don't think of a rattler in a New Jersey setting do you... but you should.

That's right, New Jersey has a native rattlesnake, the Timber Rattlesnake (Croalus horridus). The timber rattlesnake was once found throughout N.J. but now they are restricted into two very distinct populations. They occur in the rocky, wooded ledges of northern N.J. and in the pine-oak forests and swamps of the Pine Barrens. They also come in two colors, a light (yellow) phase or a dark (black) phase, and because of these variations in skin tone other snakes are often misidentified as rattlers.

Rattlesnakes are ovoviviparous, which means that they essentially lay eggs that are ready to hatch, but instead of an actual shell the baby is covered with a membrane. Most other snakes are oviparous, meaning they lay eggs that need to incubate for a period of time externally before they hatch.

Rattlesnake babies are born with what's called a "pre-button" at the end of its tail. When it sheds its skin, the skin gets caught on the pre-button and a button is formed. At the second shed, the first segment is formed and can now rattle against the button. Each time the snake sheds, a new segment is added and the rattle gets longer and louder. The segments knocking against each other create the sound. However, as the snake gets older, the outer segments of the rattle can become brittle and fall off. That's why you can never tell the age of a rattler by the size of its rattle.

Timber rattlesnakes belong to the pit viper family of snakes. Pit vipers have a special heat sensing system that allows the snake to sense body heat from other animals. This pit is a special organ located between the eyes and the nostril. Additionally, rattlesnakes have the most highly developed venom system of all snakes. The hemotoxic venom is produced in glands behind the eyes, and then flows through ducts into hollow fangs. The fangs fold back against the roof of the mouth, but when the snake strikes, the fangs are pivoted forward to inject venom, the amount of which the snake can control.

The Timber Rattlesnake is listed as a N.J. State Endangered species because of habitat loss, road-side mortality, unjustified killing and illegal collecting. Rattlesnakes are basically a passive animal and are a very important part of a healthy ecosystem, helping to control prey such as rodents. They are also prey themselves for a variety of raptors. So if you should be lucky enough to come across a Timber in the wilds of N.J. do not approach it and never attempt to handle it. But appreciate it as the ecologically friendly rodent exterminator that it is.


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