The pocket gophers are burrowing rodents of the family Geomyidae. These are the "true" gophers, though several ground squirrels of the family Sciuridae are often called gophers also. The name "Pocket Gopher" on its own may be used to refer to any of a number of subspecies of the family.
Distribution
Pocket Gophers are widely distributed in
North America, extending into
Central America.
Appearance
Gophers are heavily built, and most are moderately large, weighing a few hundred
grams. A few
species reach weights approaching one
kg. Most gophers have brown
fur which often closely matches the color of the
soil in which they live. Their most characteristic feature is their large
cheek pouches, from which the word "pocket" in their name derives. These pouches are fur-lined, and can be turned inside out. They extend from the side of the
mouth well back onto the
shoulders.
Behavior
All pocket gophers are
burrowers. They are
larder hoarders, and their cheek pouches are used for transporting food back to their burrows. Gophers can collect large hoards. Their presence is unambiguously announced by the appearance of
mounds of fresh dirt about 20
cm in
diameter. These mounds will often appear in
vegetable gardens,
lawns, or
farms, as gophers like moist soil. They also enjoy feeding on vegetables. For this reason, some species are considered agricultural
pests. They may also damage trees in
forests. Although they will attempt to flee when threatened, they may attack other animals, including cats and humans, and can inflict serious bites with their long, sharp teeth.
Classification
There has been much debate among
taxonomists about which races of pocket gopher should be recognised as full species, and the following list cannot be regarded as definitive.
- Family Geomyidae
- Genus Cratogeomys; some authors treat this genus as a subgenus of Pappogeomys.
- Genus Geomys - eastern pocket gophers; principally found in the south-western United States, east of the Sierra Nevada mountains.
- Genus Orthogeomys - giant pocket gophers or taltuzas; found in Mexico and Central America.
- Genus Pappogeomys; found in Mexico.
- Genus Thomomys - western pocket gophers; widely distributed in North America, extending into the northwestern US, Canada and the southeastern US.
- Thomomys bottae; many subspecies, including the Botta's, Fish Spring, Bonneville, Clear Lake, San Antonio, Pistol River, Mount Ellen, Guadalupe, Limpia, Mearns', Stansbury Island, Antelope Island, Cebolleta, Salinas, Skull Valley, Swasey Springs, Harquahala and Limpia Greek Pocket Gophers.
- Camas Pocket Gopher (T. bulbivorus)
- Wyoming Pocket Gopher (T. clusius)
- Idaho Pocket Gopher (T. idahoensis)
- Mazama Pocket Gopher (T. mazama); several subspecies including the Western, Gold Beach, Olympic, and Tacoma Pocket Gophers.
- Mountain Pocket Gopher (T. monticola)
- Northern Pocket Gopher (T. talpoides); very widely distributed; several subspecies including the Cheyenne Northern Pocket Gopher
- Townsend´s Pocket Gopher (T. townsendii)
- Southern Pocket Gopher (T. umbrinus)
- Genus Zygogeomys
Some sources also list a genus Hypogeomys, with one species, but this genus name is normally used for the Malagasy Giant Rat, which belongs to the family Nesomyidae.
Gopher trapping
Gopher
traps can be employed to kill them. These traps are very effective and need not be
baited. To deploy the trap, a hole must be dug in a fresh gopher mound to uncover the
tunnel. The cocked trap is inserted jaws-first so that the entire trap is within the tunnel, and then it is covered with dirt. The gopher will push against the trigger plate in order to reacquire access to the hole which has been blocked. In doing so, it will position its body directly above the jaws. When the jaws close, they will break the gopher's spine in the best case or merely maim the animal in the worst case. This method of gopher control is allowable in certified organic operations as there are no non-organic chemicals used. Mounds made by
moles are different, with the dirt being more finely broken up, and gopher traps are ineffective against moles.
To make your traps more effective, realize that the mound is always set off a foot or two from the main run. Dig (or probe with a thin rod) until you locate the tunnel going in both directions; then put a trap in each hole. Cover with dirt, as above, and wait 24 hours. Gophers are very sensitive to light, and will fill in their tunnels and abandon them if they perceive any light, so it is important to cover all openings where light might come in after setting a trap. Placing a board larger than the hole over the opening and covering all edges around it with dirt will seal off light so that the gopher does not abandon the tunnel.
Gopher gas poisoning and poison baiting
Another non-organically certified method of gopher extermination is to inject toxic nerve gases such as
aluminum phosphide into the tunnels. This is also often followed with the insertion of poison bait pellets in to the central nest areas for longer term control. This method has created controversy as aluminum phosphide is a federally registered pesticides with known hazards to human health.
A Cheap method of Gopher removal is to place an ignited road flare in the tunnel. Another method is to flood the tunnels with water.
Other Extermination Methods
Farmers and ranchers have developed some ingenious ways of exterminating gophers besides trapping, shooting or poisoning. One enterprising person uses a large sewage vacuum truck to suck gophers out of dens and into the truck's tank. Another person developed a process that fills the burrows with a mixture of oxygen and propane and then ignites the gas mixture which kills the gophers with a concussive force that also collapses the tunnel systems. While both solutions are effective, gophers from outside of the treated areas will eventually spread back into the area.
At least two companies manufacture products that use the concussive force of ignited gasses: Rodenator Pro and Rodex.
External links
Rodents | Geomyoid rodents
Taschenratten | Geomyidae | Goferiniai | Goffers | Geomyidae | Гоферовые