Rattlesnakes are very often misunderstood. Sometimes they are seen as heartless creatures that will attack humans. This is absolutely not true. Rattlesnakes are very unique reptiles that don’t want to be bothered and play a very important part in the ecosystem which has major benefits throughout the entire food chain, even for humans. While rattlesnakes are venomous they will not bite you intentionally. In fact that’s why they have their rattle, to warn people of their presence so that you don’t get hurt and they don’t get hurt. We have put together useful information to help you learn about the importance of these amazing animals and be able to identify them to help gain a better understanding of their behavior and steps you can take if you encounter one near your home or in the wild. Below you can learn about TRUTH about these snakes and see some examples of rattlesnakes that live in San Diego.
The Southern Pacific Rattlesnake
Rattlesnakes are abundant in southern California, they even live right here in San Diego. One specific example is the Southern Pacific Rattlesnake or the Crotalus helleri. They are the only rattlesnake found at Cabrillo national monument. They are also found in Santa Barbara, Ventura, Los Angeles, Orange County, and Mexico. Their habitats include grasslands, rocky deserts, and agricultural fields.
What do they Look Like?
Rattlesnakes have a very distinctive shape and are fairly easy to identify. The Southern Pacific Rattlesnake is 24 to 55 inches in length and is a variety of browns with a lighter shade of hexagonal shapes on its back. Unlike other non-rattlesnakes it has a large triangular head with vertical eyes and a rattle at the end of its tail.
Is it venomous?
Yes, South pacific rattlesnakes are dangerously venomous, but as mentioned before, they do not intentionally bite humans. They mainly hunt for small rodents and sometimes rabbits. Later on we’ll explain more about what to do if you see one in the wild.
Importance of southern pacific rattlesnakes
Even though it might not seem like it, rattlesnakes are very important to the environment. They help control the rodent population, ensuring the balance of the ecosystem, and prevents the spread of diseases. Rattlesnakes on average consume 21 rodents per year, eating 25% of the rodent population in their respective area.
Another snake found very close to San Diego is the Red Diamond rattlesnake or the Crotalus ruber. Out of all the snakes on this page
This is one of the easiest to identify due to its distinctive red scales. They are a species of pit viper found in Southwestern California, Baja California, and Mexico. They live in a mostly coastal zone, in the mountains, and in the desert. Like all rattlesnake species they are venomous, but has one of the least potent venom, but still needs medical treatment
What do they look like?
C. ruber can grow to 55 inches in length but the largest ever recorded was 64 inches. As said before they are very red all over the body with orange and white stripes going down along their back.
What do they eat?
C. ruber, like all rattlesnakes, will eat small mammals like mice and rabbits. When they hunt, they ambush the small rodents with a sudden strike and venom, then the snake swallows the prey whole. This specific species of rattlesnake uses heat sensors on the side of its head to sense prey.
Importance of Red Diamonds
As predators of their ecosystem, red diamonds control the rodent population much like other rattlesnakes. This can have positive impacts on other species and plant life. Red diamonds are considered a species of special concern meaning they are legally protected to ensure their survival because of their status of high risk. Here is a link to learn more.
The speckled rattlesnake or the Crotalus mitchellii is one of the smaller species found in San Diego. It was named in honor of Silas Weir Mitchell, an American medical doctor studying rattlesnake venom. They are found in northwestern Mexico, southern California, Nevada, Utah, and western Arizona. They prefer rocky areas like deserts, and chaparral ecosystems. Like most rattlesnakes, C. mitchelli is primarily nocturnal.
What do they look like?
This snake does not grow past 39 inches, including the rattle. They are one of the smaller rattlesnakes in San Diego. This species is known for its intense variation of color patterns that ranges from orange, to red, pink, yellow, and light blue.
What do they eat?
Just like other rattlesnakes, Speckled rattlesnakes will eat small mammals, lizards, and birds.
Importance of Speckled
These rattlesnakes will consume rodents that carry seeds. When the snake eats the rodent the seed remains intact in the stomach. Then when the snake defecates it will spread the seeds over long distances.
Encountering a rattlesnake is a very lucky find, but to some people it may be terrifying. If you are one of these people who are scared of rattlesnakes, there's really nothing to worry about. Here's what you need to know in order to keep yourself and the snake safe.
Most people think that rattlesnakes want to bite you and that they are highly aggressive. This is not true, no rattlesnake is aggressive. Rattlesnakes will always try to avoid any conflict with humans and survive without stress.
Usually before you see a rattlesnake you will definitely hear it. When you do see the snake it might be standing tall and shaking its rattle but this is not aggression. This is a warning saying that the snake is there and it doesn’t want to be bothered. Us humans are too big for rattlesnakes so they have no reason to attack us. If rattlesnakes were aggressive however, then we wouldn’t be able to go on hikes.
Then why do they bite us? As said before they do not do this intentionally, they are defending themselves. They don’t know if you are a threat or not so they defend themselves if you get too close.
So here's some guidelines on what to do when you see a rattlesnake
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Usually you’ll hear the rattle sound before you see it so try to locate the snake
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make sure to stay at least 10 feet away. DO NOT touch the snake.
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Do not try to kill the snake because that raises the chances of the snake biting you and it is illegal to kill the red diamond rattlesnake.
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Always keep your dog on a leash so that it doesn’t get bit
Conclusion
Rattlesnakes live in San Diego and are not out to get you. They are animals just like you and every other animal on the planet. They play an important role in the food web by keeping the rodent population down while also serving as food for larger birds of prey. Without rattlesnakes the balance of the food chain would break since they are such a vital part of it. Rattlesnakes deserve our respect, but you can still observe these unique reptiles from a safe distance.
Frequently asked questions
What are rattlesnake tails made of?
Rattlesnake tails are made of interconnecting hollow segments made of keratin. These are also known as rattles which are loosely connected. This material is the same thing that your nails are made of.
How old can rattlesnakes live?
Despite their small size the rattlesnake can live up to 10 to 25 years old. In rare cases they can live to 30 years old.
What is the largest rattlesnake in the world?
The eastern diamond rattlesnake (Cortalus adamanteus) is the largest rattlesnake in the world. It can grow to 7-10 feet in length and weigh 34 pounds. Along with its largest size it has one of the most dangerous venoms in the United states. This snake however is not in San Diego, but lives in areas of North Carolina, Florida, Alabama, and Mississippi. Its habitats include dry pine forests, salt marshes, and flatwoods. In these areas it likes to steal the borrows made by gophers and gopher tortoises.
Are rattlesnakes the top predator in their area?
To put it simply, no. Rattlesnakes play an important role in the middle of the food chain by eating rodents. They are, however, eaten by other larger species such as the badger, eagles, vultures, hawks, bobcats, coyotes, and California kingsnakes.
What is the survival rate of a rattlesnake bite?
Even though rattlesnakes have dangerous venom, you have a very high chance of surviving. Fatalities from rattlesnakes are very rare, especially when medical care is very widespread. It is estimated that 1 in 600 rattlesnake bites are fatal, so it is very unlikely you will die from a rattlesnake bite.
What to do if you have a rattlesnake in your backyard?
First of all you need to keep your distance and stay calm. Make sure your pets are locked up to prevent them from being bit. DO NOT try to handle the snake yourself, call any San Diego animal services.
Image Credit
https://depositphotos.com/photos/southern-pacific-rattlesnake.html
https://sdmmp.com/view_species.php?taxaid=174316
Tom Derr - rattlesnake specialist
References
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Wikipedia Contributors. “Crotalus Helleri.” Wikipedia, Wikimedia Foundation, 6 May 2025.
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“Snakes - Cabrillo National Monument (U.S. National Park Service).” Nps.gov, 2024, www.nps.gov/cabr/learn/nature/snakes.htm. Accessed 14 May 2025.
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“What to Do If You Encounter a Rattlesnake.” Wildlife.utah.gov, wildlife.utah.gov/news/utah-wildlife-news/1202-rattlesnake-encounter-what-to-do.html.
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“Arizona Hikers’ Guide to Rattlesnake Safety - Rattlesnake Solutions.” Https://Rattlesnakesolutions.com, 21 Mar. 2018, rattlesnakesolutions.com/snakeblog/arizona-snakes/arizona-hikers-guide-to-rattlesnake-safety/. Accessed 16 May 2025.
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“Red Diamond Rattlesnake - Crotalus Ruber.” Californiaherps.com, californiaherps.com/snakes/pages/c.ruber.html.
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Southwestern Speckled Rattlesnake. “Southwestern Speckled Rattlesnake – Arizona Snake Identification and Information.” Rattlesnakesolutions.com, 2025, rattlesnakesolutions.com/snake-information/roa-southwestern-speckled-rattlesnake.php. Accessed 16 May 2025
