August 1, 2015
As we conserve precious water you may be wondering how the drought will impact the four-legged creatures that share the bounty of Marin County with us. Well, it’s a good news-bad news kind of story.
To get the scoop on the repercussions of the drought and limited food supplies on animals such as deer, raccoons, rats, bobcat, mountain lions, and skunks I spoke with Roger Baldwin, wildlife specialist in the Department of Wildlife, Fish and Conservation Biology at the University of California, Davis.
It’s difficult to make general statements regarding the impact of a statewide drought on these animals because access to water and food differs greatly from location to location. Marin has been blessed with more water this year than many other counties, so the impact of the drought will not be as severe for our wildlife. However, there may be some behavior changes in the animals as well as some precautions humans can take to reduce conflicts.
Mule deer (Odocoileus hemionus), blacktailed deer (O. hemionus columbianus) and other herbivores follow the shift of their food supply as vegetation changes with our seasons. Typically, we see the deer coming down from the brown hills and into our backyards at the end of summer when naturally occurring food isn’t as readily available. The reduction in food supply because of drought conditions increases the pressure to browse in our gardens. Under conditions of extreme food shortage deer eat plants they usually don’t prefer. This year, the habitat shift will probably happen earlier and deer repellents won’t be as effective — the deer may feast on sprayed plants. Fencing, at least 7 to 8 feet high, is the best option to keep your garden deer-free.
Mountain lions and bobcats will probably have enough rabbits and other prey to keep them happy in their habitat, Baldwin says. Likewise, animals such as striped skunks (Mephitis mephitis) and raccoons (Procyon lotor), called generalists for their highly adaptable omnivorous diet, have many resources available to them in suburban areas.
“Generalists thrive in many different habitats and are plastic in their behaviors,” he says. “When you have animals with narrow habitats like fishers, martins and spotted owls, they can get into more trouble when primary food sources become scarce.”
As for some of our more common vertebrates, Norway rats (Rattus norvegicus), roof rats (Rattus rattus), ground squirrels (Otospermophilus beecheyi) and tree squirrels (Sciurus), they might exhibit changes in behavior as they seek food sources that are more readily available. Between bird feeders and pet food, the suburban resident provides an ample food supply for these pests right in their backyard.
We can help reduce the close proximity of these animals by being more vigilant about eliminating garbage and bringing pet food indoors, especially at night. Secure your trash cans with bungee cords — raccoons have been known to unlock latches with their hand-like front paws. Pick up fallen fruits and nuts so you’re not inadvertently attracting the animals. Bottom line, the most effective way to make your property less attractive to vertebrate pests is by limiting their access to food, water, and shelter.
So the good news is that Marin’s wildlife won’t likely encounter severe health and welfare impacts because of the drought. The bad news is there may be an adjustment in habitat for these pests as they forage for food that brings them closer and closer to our homes and gardens. For more information on how to manage the presence of pests, go to the Statewide Integrated Pest Management website at ipm.ucdavis.edu and click on the link to home, garden and landscape pests or give the UC Marin Master Gardener help desk a call at 415-473-4204.