A Report From the Lassen County Cooperative Extension
by Cherl Lauritsen
Good Morning. My name is Cheryl Lauritsen and I am from the Lassen County Agriculture Commissioner’s Office. Winter is almost over and spring is right around the corner. Along with the warmer weather and occasional showers,spring also brings rodent and weed problems. Today we will concentrate on ground squirrels.
“How do I deal with those pesky critters?” Youmight ask. Well, according to theUCDavisIntegrated Pest Management website,the control procedure you select depends heavily upon the unique life cycle and behavior ofthe ground squirrel. For example, baiting with treated grain is effective in summer and
fall, because squirrels primarily feed on seeds during this period.
Fumigation is most effective in spring when moist soil helps seal gasses in the burrow system and because squirrels die before they can reproduce. Another method for squirrel management is the use of traps which can be used year round but is best used for control when squirrel numbers are low to moderate. Fumigation is a relatively safe method of control. As with any pesticide,read and follow label instructions carefully. Fumigating in summer or when the soil is dry is not effective because the gas more readily diffuses into small cracks present in dry soil. Likewise,fumigating during hibernation is not effective because the squirrel plugs its burrow with soil, preventing fumes from reaching the nest chamber. You can’t see this plug by examining the burrow entrance.
Anotherthing to considerin yoursquirrelmanagement programis habitatmodification. You’ll generally find ground squirrelsin open areas, although they sometimes use available cover. Remove brush piles and debristomake an area less desirable. This also aidsin detecting squirrels and their burrows and
improves access during control operations.
Ground squirrels can reinvade a site by moving into vacant burrows.Destroy old burrows by deep ripping them to a depth of at least 20 inches, using a tractor and ripping bar(s). Simply filling in the burrows with soil does not prevent reinvasion, as ground squirrels easily find and reopen old burrows.
For those who live next to wildlands or other areas where squirrels are common, an ongoing control program will be necessary,since squirrels will reinvade overtime.Once you have controlled ground squirrels, periodically monitor the area for reinfestation. Check for new burrows, and start control actions as soon as you notice new arrivals.
It is easier and less expensive to control a small population. For more information contact our office or check out the UCGround Squirrel Best Management
Practices Web site, and the UC Vertebrate Pest Control Education Web site.
Lastly,since the weeds are starting to emerge, please be sure to make an appointment with our office to renew yourOp IDor Restricted Materials permit. We can be reached at 251‐8110. Thank you and happy hunting!
