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Pocket gophers
Temporal range: Early Oligocene–Recent
Botta's pocket gopher (Thomomys bottae)
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Mammalia
Order:
Rodentia
Superfamily:
Geomyoidea
Family:
Geomyidae

Bonaparte, 1845
Genera

Cratogeomys
Geomys
Orthogeomys
Pappogeomys
Thomomys
Zygogeomys

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 as well. The name "pocket gopher" on its own may be used to refer to any of a number of genera within the family.

Distribution

Pocket gophers are widely distributed in North America, extending into Central America.

Appearance

Gophers are heavily built, and most are 12 to 30 cm (4.7 to 11.8 in) long, weighing a few hundred grams. A few species reach weights approaching 1 kg (2.2 lb). Within any species, the males are larger than the females and can be nearly double their weight.[1] Most gophers have brown fur that often closely matches the color of the soil in which they live. Their most characteristic features are 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. They have small eyes and a short, hairy tail, which they use to feel around tunnels when they walk backwards.

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 (7.9 in) in diameter. These mounds will often appear in vegetable gardens, lawns, or farms, as gophers like moist soil (see Soil biomantle). 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.

Pocket gophers are solitary outside of the breeding season, aggressively maintaining territories that vary in size depending on the resources available. Males and females may share some burrows and nesting chambers if their territories border each other, but in general, each pocket gopher inhabits its own individual tunnel system.

Depending on the species and local conditions, pocket gophers may have a specific annual breeding season, or may breed repeatedly through the year. Each litter typically consists of two to five young, although this may be much higher in some species. The young are born blind and helpless, and are weaned at around forty days.[2]

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.

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.

Control

Geomys spp and Thomomys spp are classed as "prohibited new organisms" under New Zealand's Hazardous Substances and New Organisms Act 1996 preventing it from being imported into the country.[3]

FUMIGANTS Vehicle Exhaust Pipe / carbon monoxide Some form of hose such as a dryer vent line or garden hose can be placed into the gopher tunnel. The other end of the hose can be attached to an adapter which is attached to the exhaust pipe of a vehicle. By allowing the engine idle for 20-30 minutes enough carbon monoxide may fill the tunnel system so the gophers will fall unconscious before death occurs.

A practical concern with this method of control is that the fumes actually have to make it to where the varmint may be. It's very possible that parts of the tunnel are closed off to where the gopher is located and the fumes won't make it there. Plus, the further the hose is pushed into the hole, dirt starts to plug up the hose itself. The gopher may actually begin to back fill the tunnel upon noticing the presence of a noxious gas.

An alternative to creating an adapter/ hose device is a commercial device on the market. The commercial device is a properly sized tool that delivers a large volume of toxic exhaust to a burrow without causing harm to the exhaust source. It funnels the toxic exhaust from your car, truck, tractor or lawnmower into the burrow via a special hose. Gas Bombs Ignitable gas bombs look like a fireworks product or a small stick of dynamite. To use these, one must clear out the entrance to the tunnel, ignite the gas bomb, place it into the hole, and cover the hole with sod or dirt, so the smoke goes into the tunnel. After a couple of days, just dig up the spent cartridge and rake out the dirt into your yard.

One may not know if they have succeeded in getting eliminating the gopher until new mounds of dirt appear. If the tunnel is blocked off, the gas can't get through. Products of this sort can be fun to use and interesting to see a little smoke rising from the lawn. They come in packs of five or six.


TRAPS There are several types of gopher traps available. When placed in the gopher’s tunnel system, the traps are designed to capture and most likely kill the gopher. Most are spring loaded and provide compression around the body of the gopher to prevent escape. This is a very definitive means to know if the gopher has been eliminated successfully. It is recommended to secure the traps with a chain or stake to prevent loss of the trap down the tunnel system should the animal not be killed immediately. Baiting the trap with peanut butter, carrots or some other food source is felt to help increase effectiveness and lessen near misses by some sources. http://www.gopherguide.com/traps.html


ELECTRONICS While these devices do not kill the gopher, they are intended to chase them away from the area where they are placed.


CHEMICALS Repellents can be spread on lawns to change the flavor of the food source for the gopher to deter them from eating the roots from your lawn, trees and shrubs, possibly encouraging them to move on to more tasteful pastures. These come in hose end sprayer devices to spread in a liquid form and in granules which can be applied via a lawn spreader. It does appear that these type of products work better for moles and voles than gophers. Multiple applications may become somewhat expensive and may not be cost effective for large areas. The return on investment for this method of gopher control may be quite poor. http://www.gopherguide.com/ideas.html


EXCLUSION BY FENCING This is a labor intensive option for controlling gophers that appears to have had limited success. Leaving some fence material above ground bent to the outside of the protected area may also be required. Burying chicken fence at least 18 inches (46 cm). The mesh should be small enough to exclude gophers: 1/4-inch or 1/2-inch (6- to 13-mm). http://icwdm.org/handbook/rodents/PocketGophers.asp


FARM CROP ROTATIONS Rotating alfalfa may be helpful for gopher control. These mammals do not seem to want this as a food source.

http://icwdm.org/handbook/rodents/PocketGophers.asp


FARM GRAIN BUFFERS AROUND HAY FIELDS Planting 50foot (15-m) buffer strips of grain around hay fields provides unsuitable habitat for gophers. Possibly the regular turnover of the soil in the buffer area disturbs the burrows and creates a protective barrier for grass hay. http://icwdm.org/handbook/rodents/PocketGophers.asp


WEED CONTROL Dandelions and other large tap root plants are a prominent food source for gophers. Controlling these plants may create a less desirable habitat for gophers. http://icwdm.org/handbook/rodents/PocketGophers.asp


FLOOD IRRIGATION Water can fill a gopher’s tunnel, thus causing the vermin to drown or flee to the surface, making them vulnerable to predators. This can happen by natural means or by intentional routes. The soil may be so damp that it becomes sticky fouling the pocket gopher’s fur and claws. As the soil becomes saturated with water, the diffusion of gases into and out of the gopher’s burrow is inhibited, creating an inhospitable environment. The effectiveness of this method can be enhanced by removing high spots in fields that may serve as refuges during irrigation. This method may be impractical for typical Midwestern farms not growing rice crops or in areas with limited water availability. http://icwdm.org/handbook/rodents/PocketGophers.asp


POISONS Poisons and baits are a popular weapon against gophers. Because of their effectiveness and ease of use, they are a good choice for many users. Advantages of baits: 1. They are fairly easy to use with an applicator. 2. When applied into the pest's tunnels, the pellets generally work. 3. If the baits do their job, the critter is already buried. One does not have to empty any traps.

Disadvantages of baits: 1. Other than an absence of new mounds, one is not sure if the pests are eliminated or not. 2. While working with poisons, one has to be careful when applying them (spilling some aboveground) and storing them carefully. 3. They may not be available for sale in all states. http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7433.html


SHOOTING Since these animals spend most of their time in their tunnels below ground, this method is impractical.


For Additional Information Alsager, D. E., ed. 1970. Control of pocket gophers. Alberta Department of Agriculture, Publication No. 686, 16 pp.

Alsager, D. E. 1977. Impact of pocket gophers (Thomomys talpoides) on the quantitative productivity of rangelands vegetation in southern Alberta: A damage assessment tool. Pages. 47-57 in W. B. Jackson, and R. E. Marsh, eds. Test methods for vertebrate pest control and management materials, ASTM STP 625, Am. Soc. Testing Mater. Philadelphia, Pennsylvania.

Andersen, D. C. 1978. Observations on reproduction, growth, and behavior of the northern pocket gopher (Thomomys talpoides). J. Mammal. 59:418-422.

Anthony, R. M., V. G. Barnes, Jr., and J. Evans. 1978. “Vexar” plastic netting to reduce pocket gopher depredation of conifer seedlings. Proc. Vertebr. Pest Conf. 8:138-144.

Barnes, V. G., Jr. 1973. Pocket gophers and reforestation in the Pacific Northwest: a problem analysis. US Fish Wildl. Serv. Special Sci. Rep. Wildl. No. 155. Washington, DC. 18 pp.

Chase, J. D., W. E. Howard, and J. T. Roseberry. 1982. Pocket gophers. Pages. 239-255 in J. A. Chapman and G. A. Feldhamer, eds. Wild mammals of North America: biology, management, and economics. The Johns Hopkins Univ. Press, Baltimore, Maryland.

Connolly, R. A., and R. E. Landstrom. 1969. Gopher damage to buried cable materials. Mater. Res. Standards 9:13-18.

Corbet, G. B., and J. E. Hill. 1986. A world list of mammalian species. 2d ed. Facts On File Publ., New York. 254 pp.

Downhower, J. F., and E. R. Hall. 1966. The pocket gopher in Kansas. Univ. Kansas Museum Nat. Hist., Misc. Publ. No. 44. 32 pp.

Fitch, H. S., and J. R. Bentley. 1949. Use of California annual-plant forage by range rodents. Ecology. 30:306-321.

Foster, M. A., and J. Stubbendieck. 1980. Effects of the plains pocket gopher (Geomys bursarius) on rangelands. J. Range Manage. 33:74-78.

Hegdal, P. L., and T. A. Gatz. 1976. Hazards to wildlife associated with underground strychnine baiting for pocket gophers. Proc. Vertebr. Pest Conf. 7:158-266.

Hegdal, P. L., and A. J. Harbour. 1991. Pocket gophers. Pages 5-19 in Prevention and control of animal damage to hydraulic structures. United States Printing Office, Denver, Colorado.

Hickman, G. C. 1977. Geomyid interaction in burrow systems. Texas J. Sci. 29:235-243. H ickman, G. C. 1977. Swimming behavior in representative species of the three genera of North American geomyids. Southwest Nat. 21:531-538.

Howard, W. E. 1961. A pocket gopher population crash. J. Mammal. 42:258-260.

Kennerly, T. E., Jr. 1958. Comparisons of morphology and life history of two species of pocket gophers. Texas J. Sci. 10:133-146.

Laycock, W. A., and B. Z. Richardson. 1975. Long-term effects of pocket gopher control on vegetation and soils of a subalpine grassland. J. Range Manage. 28:458-462.

Luce, D. G., R. M. Case, and J. Stubbendieck. 1980. Food habits of the plains pocket gopher on western Nebraska rangelands. J. Range Manage. 33:129-131.

Luce, D. G., R. M. Case, and J. L. Stubbendieck. 1981. Damage to alfalfa fields by plains pocket gophers. J. Wildl. Manage. 45:258-260.

Marsh, R. E. 1992. Reflections on current (1992) pocket gopher control in California. Proc. Vertebr. Pest Conf. 15:289-295. M arsh, R. E., and M. W. Cummings. 1977. Pocket gopher control with mechanical bait applicator. Coop. Ext., Div. Agric. Sci., Univ. California Leaflet 2699. 7 pp.

Miller, M. A. 1957. Burrows of the Sacramento Valley pocket gopher in flood-irrigated alfalfa fields. Hilgardia 26:431-452.

Myers, G. T., and T. A. Vaughan. 1964. Food habits of the plains pocket gopher in eastern Colorado. J. Mammal. 45:588-598. Radwan, M. A., G. L. Couch, C. A. Harrington, and W. D. Ellis. 1982. Terpenes of ponderosa pine and feeding preferences by pocket gophers. J. Chem. Ecol. 8:241-253.

Reichman, O. J., T. G. Whitham, and G. A. Ruffner. 1982. Adaptive geometry of burrow spacing in two pocket gopher populations. Ecology. 63:687-695.

Schwartz, C. W., and E. R. Schwartz. 1981. The wild mammals of Missouri, rev. ed. Univ. Missouri Press, Columbia. 356 pp.

Sudaman, P. D., J. C. Burns, and J. R. Choate. 1986. Gestation and postnatal development of the plains pocket gopher. Texas J. Sci. 38:91-94.

Turner, G. T., R. M. Hansen, V. H. Reid, H. P. Tietjen, and A. L. Ward. 1973. Pocket gophers and Colorado mountain rangelands. Colorado State Univ. Exp. Stn. Bulletin 554S. 90 pp.

Vaughan, T. A. 1962. Reproduction in the plains pocket gopher in Colorado. J. Mammal. 43:1-13.

http://icwdm.org/handbook/rodents/PocketGophers.asp


Case, R. M., and B. A. Jasch. 1994. Pocket gophers. In S. E. Hygnstrom, R. M. Timm, and G. E. Larson, eds. Prevention and Control of Wildlife Damage. Vol. 1. Lincoln: Univ. Neb. Coop. Ext. pp. B.17–29.

Ingles, L. G. 1965. Mammals of the Pacific States: California, Oregon, Washington. Stanford: Stanford Univ. Press. 506 pp.

Salmon, T. P., D. A. Whisson, and R. E. Marsh. 2006. Wildlife Pest Control around Gardens and Homes. 2nd ed. Oakland: Univ. Calif. Div. Agric. Nat. Res. Publ. 21385. 122 pp.

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7433.html

References

  1. ^ Macdonald (Ed), Professor David W. (2006). The Encyclopedia of Mammals. Oxford University Press. ISBN 0-19-920608-2. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)
  2. ^ Patton, James (1984). Macdonald, D. (ed.). The Encyclopedia of Mammals. New York: Facts on File. pp. 628–631. ISBN 0-87196-871-1.
  3. ^ Hazardous Substances and New Organisms Act 2003 - Schedule 2 Prohibited new organisms, New Zealand Government, retrieved 26 January 2012
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