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Pocket Gopher. Glenn Sulzberg. Pocket Gopher Overview. Burrowing rodent – get their name from the fur-lined, external cheek pouches, or pockets, they use for carrying food and nesting materials Very prevalent in the western 2/3 of the US
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Pocket Gopher Glenn Sulzberg
Pocket Gopher Overview • Burrowing rodent – get their name from the fur-lined, external cheek pouches, or pockets, they use for carrying food and nesting materials • Very prevalent in the western 2/3 of the US • 5 species found in California – most prevalent Thomomysbottae • Range from 5 to 14 inches in length • Forepaws are large-clawed • Large incisors used for digging and burrowing
Pocket Gopher Lifecycle • Birth rates and breeding • Gestation 18 days • Up to 4 litters a year depending weather conditions • 3 to 4 pups on average per litter can be as high as 12 • Average life span 1 to 3 years • Young born blind and helpless weaned around 40 days • Lifestyle • Usually inhabit their own tunnel system • They are solitary outside of breeding season
Pocket Gopher Damage • Damage to property • Burrow systems loosen soil can create erosion issues • Mounds can interfere or damage equipment • Ruin aesthetics of the site • Damage to sprinkler infrastructure • Damage to plants • 3 ways they feed on plants • feed on roots • feed above ground on vegetation • pull plants into the burrow • Grapevines are damaged when gophers chew on roots or bark below the soil line. • Vines damaged in this way will look water stressed or will die as a result of girdling
Pocket Gopher Monitoring & Management • Monitoring for signs and symptoms of Gophers should be done every time anyone enters the vineyard. • With potential 4 generations a year and 3 to 4 per litter monitoring is essential • Many different types of controls available • Need to assess cost benefit based on the controls chosen • Need to assess labor required for each type of control
Pocket Gopher Management • Biological Control • The gopher has a number predators that can be used to control them: snakes, hawks, owls, skunks & coyote (effective) • Environmentally friendly alternative for gopher control • Services for hire that can bring hawks or snakes to your location • Not that effective when there is an established gopher population • Gophers are underground most of the time so can be difficult for the predator to capture • If you don’t already have the predator at your site you need to bring them in
Pocket Gopher Management • Chemical Control options- • Fumigation – aluminum phosphide (very effective) • Very effective when soils are moist • Requires certification and license to apply • Poison – zinc phosphide, strychnine, anticoagulant baits (very effective) • Can be very effective when baited properly • Dangerous to other animals or humans • Fumigation – road flares or car exhaust (marginally effective) • Not legal in California, not very effective in large areas or large established populations • Fumigation – gasser sulphur sticks (marginally effective) • Effective for a small area. • The gophers can block the burrows blocking the gas
Pocket Gopher Management • Mechanical & Physical Controls • Traps (very effective) • Different types of traps, can be very effective if used properly. Very effective when paired with fumigation. • Burrow Flooding (marginally effective) • Forces them out of their burrows or traps and kills them. Can cause erosion and also if they are able to escape they can re-establish • Rodinator (marginally effective) • Destroys burrows and kills gophers. Not as effective when there are large populations. Can be dangerous. • Vibrating stakes or sonic stakes (not effective) • Not very effective, gophers get desensitized to them. Can be expensive for large areas and establish populations.
Pocket Gopher Management • Cultural Control • Removal of plant materials removes habitat and food sources (marginally effective on its own) • Removes protection from predators • Can help contain in certain areas but won’t rid you of existing populations • Low cost method for control • Can lead to more effective use of other controls in conjunction with this control.
Pocket Gopher Recommendations • Use multiple controls if possible • Do not wait to treat once signs or symptoms appear, with up to four birth cycles a year populations can grow rapidly. • Monitor your site on a schedule • Track any activity and their locations • Be diligent, be diligent, be diligent