By Kelsey Grousbeck, Intern
As you make your way around Jasper Ridge and surrounding hills, it’s not just the rock formations that are serpentine. The Northern Pacific Rattlesnake (Crotalus viridis oreganus) is native to Northern California and breeds in the late summer, favoring these rocky grasslands for their habitat. Though rattlesnakes strike fear into many hikers, that is typically all the striking they do. The California Department of Fish and Game assures hikers that attacks are accidental and, unless provoked, these snakes favor retreat and give clear warning signs (such as their rattle) before attacking (http://www.dfg.ca.gov/news/issues/snake.html).
The Northern Pacific Rattlesnake is also found in mixed woods and sagebrush from central California up to Washington and British Columbia, extending into parts of Idaho. Depending on their surroundings, their coloring can vary from olive to gray or tan with darker blotches. They get to be an average length of about 2 feet, with some as long as 5 feet, and in the wild it is estimated they live to be about 15 years old. Their prey consists of reptiles, amphibians and small rodents, though the adult California Ground Squirrel has developed immunity to their venom and responds aggressively if attacked.
Though they breed in the summer, rattlesnake females store the sperm and do not reproduce until the following spring. A female Northern Pacific Rattlesnake can reproduce only once every three years because they must double their body weight before pregnancy. The increased weight allows them to survive since they fast for almost 19 months during pregnancy and the following hibernation period. Females give birth to about 2-8 live young in mid-September. These young have underdeveloped “buttons” where their rattles will be, which they do not fully develop until they are over a year old. Juvenile rattlesnakes, despite not having developed rattles, still contain as much venom as adults.
Rattlesnake bites are rarely fatal to humans, so if you have been bitten don’t panic. Instead, rinse the wound with soap and water, remove anything that may constrict swelling such as watches or rings, apply a cool, wet cloth to the area and get to a hospital or poison control center as soon as you can. Do not apply a tourniquet or ice to the bite and never cut the wound or try to suck the venom out with your mouth, as those practices can end up harming you further.
To avoid an unfavorable interaction with a rattlesnake, be sure to wear proper hiking boots and long pants while hiking in areas that could be snake habitat. Additionally, step on top of rocks or stumps as opposed to over them, since snakes enjoy resting against the side of these trail obstacles. To be extra cautious, use a walking stick to prevent a threatened snake from attacking if you accidentally walk too close.
The most important fact to remember when you come across a rattlesnake is that they are a threatened species and should be respected and left alone. Once you know how to avoid engaging a rattlesnake, hiking in the summer and fall can be very exciting, especially when you can try to spot young rattlesnakes before they head to their burrows to hibernate. So happy trails and beware any ominous rattle sounds!
Edit: These photos were taken yesterday by Audrey at Russian Ridge Open Space Preserve!
And a neat video from Animal Planet (Thanks, Audrey!):










For those who haven’t heard it, the “rattle” of a rattlesnake is more of a buzz, reminding me of the sound of the self-timer on some cameras.
When I worked at Henry Coe State Park through the 90s, all definite cases of rattlesnake bites, and all recorded from the previous decades, resulted when a male visitor picked up or tried to pick up a rattlesnake. The classic case was that of a Boy Scout leader picking one up to show the scouts how to handle them–and getting bit!
There was a case of a woman reporting a wound on the leg from what she thought was a stick striking her. The first aid volunteer was fairly sure it was a rattlesnake bite, but there was no swelling involved, and if so, it may have been a “dry” strike. (Maybe the victim had poor vision.) A significant percentage of rattlesnakes do not inject venom when biting.
There is no guarantee that a rattlesnake will warn you before striking, but that is usually the case. If they are not alarmed at your presence for whatever reason, they may not buzz, and I’ve passed some on the trail only to notice them as I look down. More often, I’ve been startled by the buzz of a rattler as I’ve walked by; snakes I would have gone right by without noticing did put an extra hop in my step.
In general, the Northern Pacific Rattlesnake is less “aggressive” (perhaps “proactively defensive” would be a better term) than other species. The Mojave Rattlesnake (of the California deserts) is not quite so docile, and the venom is particularly toxic, and more likely to result in death if untreated than most other species.