The Northern Pacific Rattlesnake inhabits most of northern and central California, from the southern San Joaquin valley to the Oregon border (though they inhabit regions as far north of British Columbia), west to the coast. They are active from early to mid-spring (depending on weather conditions), to fall, and hibernate during from later fall and through the winter, sometimes in dens with large numbers of snakes, even of other species. They try to refrain from being active during daylight during periods of excessive heat and hunt overnight when temperatures moderate. They are commonly found moving around or seeking hunting grounds during the daytime when temperatures are more tolerable (mid/upper 60’s – 80’s), and more active at night when temperatures get hot (90 degrees or more typically).
Their appearance can vary in coloring quite a bit, but most have “spots” or blotches across their backs (to view photos, click here), but some can appear nearly patternless. Color patterns can vary from a near black color, to green, to yellow and orange tints. Most northern Pacific’s don’t grow over 3ft, but some population groups can feature some adults in the 4 – 5ft range… 5ft being quite rare. Rattlesnakes are born live, and not from eggs, and are active right after they’re born. Neonate (newborn/very young) rattlesnakes will indeed have a button at the end of their tail and are usually 10″ – 12″ in length. Neonates can take off after being born, but in many cases may hang out with their mother for a while (perhaps days, if in a favorable location).
Rattlesnakes favor rocky terrain, tall grasses or weeds, and areas with wood or other debris where they can hide or escape the heat and predators easily. In places where their habitat meets up with humans, they tend to hangout in the shade of bushes used for landscaping, gardens with plenty of cover, and under objects sitting next to a home or building so they can nestle up against the siding/wall to feel secure. They are attracted to areas with a decent food source, which includes smaller rodents such as mice, rats, voles, gophers, lizards, and even rabbits and squirrels. Main predators are hawks, eagles, king snakes, owls, house cats, and especially humans.
Rattlesnakes, given their name, acquire a new segment (also known as a “button”) to its rattle every time it sheds, which can range from a couple to several segments a year depending on the age, location, and health of the snake. You cannot tell the exact age of a rattlesnake by counting its rattle segments given the variability in shed patterns. Additionally, as they crawl through rocks and other rough debris, sections can break off and lower the total count.
Speaking of age: rattlesnakes can rack up many more years on their lives than most of us think. On average, rattlesnakes tend to live anywhere fro 7 – 10 years — however, in places where there’s less human interference, it’s possible healthy snakes can rack up double that. The oldest northern Pacific rattlesnake was a captive named Striker, who was raised by Placer High School for 31 years before being transferred to Sacramento Splash for another 3 years, when he passed away in 2015 at 34 years old due to complications with a tumor.
Rattlesnakes are not the evil beings some believe they are, and they don’t go out seeking humans to attack. It may not seem like it, but snakes are (much) more scared of us humans than we are of them. The only reason they strike is if they fear for their lives, as a last resort. Most bites occur by stepping on a snake when someone is walking or jogging, not watching where their stepping. A good amount of bites also occur when inexperienced people try to catch or kill snakes. Just give a professional a call to come out and remove one if you don’t want it around to avoid any risks you don’t have to take.
Weather and Rattlesnakes
Weather plays a major role in the amount of activity snakes engage in. After all, snakes are cold-blooded, and that goes for all reptiles, meaning the sun and other external sources of heat are what warm up their bodies and allow them to become active (and survive).
Over the last several years, I’ve noticed rattlesnakes are generally most active in temperatures between low 70s and mid-80s, and in addition to air temperatures, clouds and precipitation are also big factors. When rattlesnakes are active in the spring through early fall, monsoonal showers and thunderstorms can occasionally be present. It seems the majority of rattlesnakes enjoy monsoonal rainfall on warm to hot days, and in fact may come out of their hiding places to experience it, perhaps to cool themselves off or attempt to get a drink.
I’ve also noticed that when clouds increase during the summer, even if it’s quite warm already, it limits direct sunshine somewhat and supports more snake activity, because when the air temperature is already hot, direct sun on top of that can kill a snake if it’s exposed too long in the heat, and the clouds help to protect them from that potentially deadly heating from the sun. So, even if we’re getting some monsoonal showers or thunderstorms, or even if it’s just somewhat cloudy outside (during the summer of course), snakes may enjoy it more than we do!
Once temperatures climb into the 90s, they’ll be ducking for cover in the shade as much as they can, and once the 100s arrive, shade is about the only thing on their mind. In the 90s and 100s, snakes will become (more) nocturnal in order to move around and seek prey, as exposing themselves to the sun on a hot day could kill them if they are caught out in the open with nowhere to hide.