Friday, September 26, 2014

Shaking it Up with Rattlesnakes - by Bo Gould (intern)

The Puente Hills Preserve is home to an intricate array of native plants, mammals, birds, insects, and reptiles, among others, all of whom play a vital role in supporting the health of the ecosystem. While visiting the Preserve’s beautiful natural scenery and observing its abundant wildlife, there is a group of southern Californian natives that can be particularly exciting to meet; the rattlesnakes. If you have visited the hills recently, you may have come across signs at a trailhead warning about the dangers of this reptile. However, there are many aspects of this snake that make it a special and integral part of the Puente Hills wildlife community.

Western Rattlesnake
Red Diamond Rattlesnake
In all, there are 32 known species of rattlesnakes; 7 of which can be found in California. The Puente Hills are home to two of such species; the western rattlesnake (Crotalus viridis) and the red diamond rattlesnake (Crotalus ruber). Both species can often be observed slithering among trailside grasses, stretched out on a trail or sunbathing on rock outcrops, and can grow to be over 3 feet long. The western rattlesnake is distinguished by tan and dark-brown blotches, a triangular head with pit heat-sensors on both sides, and two internasals at the tip of its head. The red diamond rattlesnake, as its name suggests, displays reddish to tan diamond-shaped scales with black-and-white bands along its tail. The coloration of rattlesnakes helps them to effectively camouflage themselves in the environment and stay well-hidden from predators.

When these snakes shed their skin, each shedding produces a new rattle at the end of their tails. These rattles are definitive characteristics of the snake and can be heard as a warning signal to potential threats or predators. Rattlesnakes will typically give a short rattle as a warning, which will grow to a steady loud rattle if the snake feels threatened. If you hear a rattlesnake, do not move until you locate the precise location of the snake, back away slowly, and keep a safe distance. Rattlesnakes rarely strike if they are unprovoked.  Never attempt to pick up a rattlesnake!

Like all pit vipers, rattlesnakes are equipped with an exceptional set of sensory organs that help them locate prey. These include pits at the tip of their nose to sense thermal radiation from warm-blooded animals, eyes adapted to nocturnal use, and a keen sense of smell from both nostrils and sensory tissues on their tongues.

Once a prey animal is located, rattlesnakes use their quick striking ability and fangs to inject powerful hemotoxic venoms. The venom travels through the blood of the prey, causing intense swelling, pain, and tissue damage. The main prey of Puente Hills rattlers are rabbits, squirrels, rats, birds, lizards, and some insects. Though rattlesnakes are effective predators themselves, they are also heavily preyed upon by hawks, crows, foxes, raccoons, and coyotes. Thus, the ecological significance of rattlesnakes is large as they help to regulate rodent populations and provide food for other native Puente Hills species.  

Although rattlesnakes are dangerous, the likelihood of being bit is very low. If you see a snake, stay calm and slowly move away. Remember to stay on designated trails within the Preserve and scan the trail ahead. If a snake is directly in the path, keeping a safe distance and stomping your feet is usually enough to coax the rattlesnake to sun in a new spot. In the case of a snakebite, do not panic! Remove all rings, watches, and anything else in the area of the wound that may restrict blood flow. Remain calm and call 911 immediately. If treated promptly, rattlesnake bites are almost never fatal. You are more likely to be struck by lightning than to be bit by a rattlesnake.

So when on the trails, keep an eye out for this important part of the Puente Hills ecosystem and watch your step!