“County health officials are advising everyone to stay away from California ground squirrels after three were found to be infected with the plague.”
What is a ground squirrel? Do you have ground squirrels in your backyard?
If you live in a typical Santa Clarita backyard with a sprinkler in action every day, away from all wilderness areas, you will probably see squirrels that spend a major part of their time in trees. These are “tree squirrels,” and in this area they are the Eastern Fox squirrel.
I know, “Eastern” may seem strange in California, but they have totally naturalized here. It is the largest tree squirrel, and it is a strong competitor to the ground squirrel, whose population is declining.
If your backyard is on the dry side and you see squirrels coming out of a tunnel under ground, those are ground squirrels. Often, the tail of a ground squirrel is less bushy, and they keep it low to the ground, not fluffy and upright like a tree squirrel. Ground squirrels also tend to run across the ground smoothly, not hopping here and there like a tree squirrel does.
Those are general descriptions, and there is always one ground squirrel that is going to be the exception with a bushy tail.
Also, if you have been around for a while like I have, you will remember the name, “Beechey squirrel.” It is part of the Latin name; the whole name is Otospermophilus beecheyi. I must admit, I am pretty pleased that the new, accepted name is California ground squirrel.
What does it look like? It has brown fur with cream-colored spots on its back. It has a darker gray color from its head down to the middle of its back, and the underside is white.
It digs burrows, and some burrows are occupied by a group, but each animal has its own entrance.
We have many ground squirrels in Placerita Canyon, and you can easily observe them in the picnic area at the Nature Center. The burrows are dug under a tree or a hard surface, so the concrete surface where the benches are attached is a perfect place to observe the entrance to the burrow.
Mating season is in the early spring, and gestation lasts one month. The female has five to eight babies. They live in a nest on the ground or in a hidden area inside a rock pile. The babies are ready to survive on their own when they are 8 weeks old.
The ground squirrel is active during the day and sleeps at night. Because our winters are mild, they are active the whole year around, and they do not hibernate as they do in colder areas.
They eat plants, flowers, berries, seeds and fruits; sometimes they eat insects and small animals.
They are rodents, so their incisors continuously grow. That is much needed with their herbivore diet; they have to cut though roots and hard shells. At Placerita, the good acorn crop is a great source of oils and carbohydrates in their diet.
The ground squirrel is a steady source of food for hawks and coyotes. Often they are also prey for rattlesnakes, and this is where the story gets interesting.
Ground squirrels have found many techniques to escape the rattlesnake. Female squirrels with pups will chew on the skin shed by rattlesnakes and lick themselves and their pups to disguise their scent. Another technique: The squirrel quickly swishes its tail to raise its temperature and kicks sand at the rattlesnake.
For hunting, rattlesnakes rely on their pit organ, which detects infrared radiation. The message they are getting from this action by the squirrel is, “There is a big, fast-moving creature in front of me, and I should not attack.” Intimidation at its best.
Some populations of ground squirrels have different levels of immunity to rattlesnakes, but studies have not been done to understand why. However, the technique to intimidate the rattlesnake was studied in 1970 at the University of California, Davis.
When it gets hot in the summer, most adults go into a phase of inactivity called estivation. The burrow seems open at the entrance, but the squirrel plugs it with soil near the nest. It rests until the weather cools off.
Look again at this sweet little face on the photo. Shouldn’t everyone fall in love with ground squirrels? Not so. They are considered a pest by gardeners because of their burrows and the damage they do to the landscape.
Bubonic plague? Yes, it is a concern, especially if you go camping. I think I would use bug spray to minimize the risk of flea bites. That is the most common way to get the plague; a bite from the ground squirrel is also not so good.
Please, if you see a dead ground squirrel, do not touch it or even come close. If you have the symptoms – fever, chills, tender and swollen lymph nodes and shock – mention to your doctor that you go hiking a lot, and to check for the plague. It is a rare disease and the chance you have the plaque is remote, but just be aware it is around.
Ground squirrels are an interesting part of our ecosystem, and I hope you have enjoyed reviewing these facts about another creature common in California.
Evelyne Vandersande has been a docent at Placerita Canyon Nature Center for 27 years. She lives in Newhall.
Something Else to Worry About: Squirrels
