Next Friday, Feb. 2, is Groundhog Day. According to tradition, if a groundhog comes out of its hole and sees its shadow, there will be six more weeks of winter. If it doesn’t see its shadow, then there will be an early spring. Do we have groundhogs, also known as woodchucks, in Nevada? No we don’t, but this is the time of year another ground-dwelling animal starts to be active in our area: ground squirrels.
Ground squirrels can be troublesome pests. They feed on crops and ornamental plants. They rob animal feed and bird feeders. They cause problems by chewing irrigation and wiring. They can also carry plague.
It is essential to understand the ground squirrel’s life cycle to initiate a good control plan. Ground squirrels hibernate in winter. The males come out in early spring or late winter, generally February or March, but I have seen active burrows in my yard this week! The females leave the burrow soon after the males. They mate, and the female returns to the burrow to give birth to as many as eight young. If you wait to initiate a control program until after they have produced a litter, you might be dealing with 10 ground squirrels instead of two.
What are the control methods available for ground squirrels? As with any pest control plan, you must include some form of exclusion in your control program. This can be difficult with ground squirrels, as they can both climb over a fence and dig under a fence. You can shoot them, provided you are allowed to discharge firearms where you live. This can be messy and requires your constant presence. You can trap them, using either kill traps or live traps. You must use care to prevent unintended trapping of wildlife or pets.
There are several kill traps that are very effective. Follow manufacturer instructions. Live trapping is problematic: what are you going to do with the live animal you’ve trapped? You cannot legally transport that ground squirrel anywhere as it might carry plague. Your only option is to kill the animal you’ve live trapped. As with all other control methods mentioned, a trapping program is best initiated before the squirrels mate and give birth to young, as this will limit the size of infestation you have to control.
Most people elect to use a chemical control. These are poison baits put out in a bait station to avoid unintended kills of non-target animals. It is important to set up the bait station early in the season, when the ground squirrels first emerge from hibernation. Ground squirrels prefer green food, like your lawn, vegetable garden and spring bulbs.
When ground squirrels first emerge, there is very little green food available, and they are more likely to consume the bait. Later in the spring when more green food is available, they are less likely to eat the bait. Additionally, later in the spring means more squirrels to control. Setting up the bait station just as the males emerge from hibernation increases your chances of controlling a ground squirrel infestation.
Melody Hefner is the Urban IPM and Pesticide Safety Education Program assistant for University of Nevada Cooperative Extension. Have a gardening question? Ask a Master Gardener at firstname.lastname@example.org.