Question: We back on to a wildlife corridor. Our backyard is landscaped primarily with perennials. We have several bird feeders. All of these factors attract ground squirrels. We built an 8-foot waterfall, and a pair of squirrels immediately decided to make their home under it. We now have about 10 squirrels and they are eating many of the perennials (rudbeckia, coreopsis, cosmos, blanket flowers, etc.). They also eat my annuals such as poppies, sweet peas and nasturtium. Is there a list of perennials and annuals that squirrels do not like?
Answer: Lists of unpalatable plants are available for deer, gopher, jack rabbits, cottontails and rats, but I have never seen one for ground squirrels. Suffice it to say, they'll eat almost anything, perhaps with the exception of daffodils, which contain a toxic alkaloid strong enough to keep even gophers from eating them.
Mammals may reject certain plants for any number of reasons, including spines, thorns, prickly leaves or the presence of secondary chemical compounds. These compounds give off a bad taste, but can have wider-ranging effects than just tasting badly. They can also be toxic, cause intestinal distress or prevent normal digestion. These defenses protect the plant.
But a plant's resistance isn't always foolproof. Obvious examples include periods of food shortage or when a preferred food has been removed, leaving only less palatable foods available. Unlike birds, which will move to another area for better food, some mammals such as deer are likely to eat highly unpalatable foods for some time before leaving an area and finding a new home range.
In their natural habitat, ground squirrels have two distinct appetites, both of which hinge on seasonality.
In the early months of the year after they emerge from hibernation, the squirrels munch on green, leafy plants. Then, when the weather heats up and the plants dry out, their preference changes--sometimes in as short as a two-week period--and they'll begin eating seeds and nuts.
As can happen when we create unnaturally abundant environments, the squirrels have trumped you. Instead of going for acorns as they might otherwise do, they obviously prefer your little bit of paradise.
Nocturnal Ring-Tail Cats Remain Elusive
Q: Years ago, I used to see civet cats coming out from underneath our house, but I haven't seen any for more than a decade, and they seem to have disappeared. What's happened to all the civet cats that used to live in Orange County?
A: Close relatives of raccoons--ring tails are in the same family, Procyonidae, as the Asian lesser pandas and our native coatis. As such, they are hardly cats as the colloquial terms civet cat, miner's cat and cacomistle would suggest.
Part of why they're rarely seen is their extremely nocturnal behavior. More elusive than a raccoon, they're seldom seen even at dawn or dusk. They prefer broken, rocky areas near water where they rest in cracks, ledges, hollow logs and other animals' burrows, and feed on rodents, rabbits, grasshoppers, crickets and fruit, including prickly pear. Their presence under your house is a curiosity because they're rarely considered a "nuisance animal."
For the uninitiated, ring tails are smaller and more slender than raccoons with big, bat-like ears and white rings around their disproportionately large eyes. The tail has six to nine black bands alternating with white and a black tip.
Ring tails walk on tiptoe and are agile runners and climbers, often ricocheting themselves from one perch to another or along cliffs and ledges. They have the reputation of being excellent "mousers," and early settlers often kept them around the house as pets, and for rodent control.
Because their fur is so thin and there's not much meat on them, they make neither good fur-bearing nor game mammals, and are protected in California.
In the late '70s, population studies estimated there was roughly one ring tail to every five square miles in Southern California, which is a pretty low density. It may well be lower today.
Because ring tails eat much the same food as other small mammals such as raccoons, bobcats, foxes and coyotes that move in and out of our neighborhoods, it's conceivable the group under your house moved due to pressure from these other animals, a lack of prey, new construction or even excessive disturbance from neighborhood pets.
With Ants, Know Your Opponent