Rodent Damage Costing Agriculture Industry Millions

Prairie dog populations tend to grow exponentially when left uncontrolled.  They will denude the land where they build their burrow mounds which can lead to erosion and weed infestations. The PERC system can help you control the issue.

For optimum treatment each burrow showing activity should be treated. Treatment time per burrow is approximately 5 minutes.  Dirt is shoveled into the burrow opening during treatment to ensure the carbon-monoxide is pushed into the burrow system and it marks the burrows that have been treated.

Three species of prairie dogs are found in Colorado.

Prairie dogs occupy an estimated two million acres in North America. Three species of prairie dogs are found in Colorado. The black-tailed prairie dog lives on the eastern plains, the Gunnison prairie dog in the southwest third of the state, and the white-tailed prairie dog in the northwest third of the state.

• Prairie dogs can carry five different diseases, each of which can be fatally transmitted to humans
• Prairie dogs can damage rangeland.
• Prairie dogs have at least one litter per year and 6-10 pups per litter.

Prairie dogs are relatively large burrowing ground squirrels that weigh 1-1/2 to 3 pounds and are 14 to 17 inches long. Prairie dogs have reddish fur, large eyes, short ears, and broad round heads.

Prairie dogs from colonies arecommonly referred to as prairie dog towns. Small groups, generally composed of one adult male, three adult females, and six offspring, defend their territory within the larger town. They live in burrows about 10 yards apart, 3 to 14 feet deep, and 10 to more than 100 feet long. A mound 3 to 10 feet across and 1/2 to 1 foot high at the entrance of the burrow prevents water from rushing in and serves as a lookout station. A density of 35 black-tailed prairie dog mounds per acre is common, although up to 95 mounds have been reported. Burrow systems have one to three entrances. Black-tailed prairie dog numbers vary from about five per acre in late winter to 20 per acre after the birth of pups in spring. Spring densities can be as high as 35 per acre.

Prairie dogs are active only during the day. White-tailed and Gunnison's prairie dogs hibernate from about October to March, depending on elevation. Black-tailed prairie dogs do not hibernate but will stay below ground for several days during cold, cloudy weather. They have one litter of three to eight young per year in March or April. The gestation period is 28 to 34 days. Pups venture above ground when they are five to six weeks old. Most prairie dogs travel two miles, but a few migrate up to six miles.

Prairie dogs are hosts for fleas, making them susceptible to bubonic plague. Plague is transmitted to humans via flea bites. Early symptoms of plague include swollen and tender lymph nodes, chills, and fever. Early diagnosis and treatment are imperative. When walking through suspected plague areas, apply an insect repellent to socks and pant cuffs before tucking pants inside boots.

Quick Gopher Facts:

• Solitary rodents that live one animal to a burrow system.
• Burrow systems are kept closed with holes plugged by the gopher.
• Gophers eat plant roots, especially alfalfa roots, damaging or killing the plants.
• Gophers do not hibernate and are active year-round. Mound building is most active in the spring and fall as well as after sprinkler irrigation.
• Burrow systems are usually two-tiered; that is, subsurface burrows that lead to the mound or the surface for shallow root feeding. A lower burrow or lateral is from six inches to twelve inches deep (or deeper) and connects mounds and feeding laterals.
• A single burrow system can be 600 lineal feet and have 100 cubic feet of air space to fill with a fumigant.
• In ideal conditions, gophers can have three litters a year with 2 to 6 pups per litter.
• Sprinkler irrigation provides ideal conditions for gophers.
• Gopher infestations can have 100 rodents or more per acre and can cause crop loss of a ton of hay per acre.
• Machinery breakdowns from gopher mounds cause harvest delays as well as repair expenses.
• Severe infestations that have depleted plant stands should probably not be treated but worked up and replanted.
• Young crop stands (2 to 5 years) can be profitably treated if crop stands have not been irreparably damaged.
• Flooding can reduce gopher infestations, but if the gophers are not killed at the time of flooding, with shovels, etc., they will continue to multiply and cause crop damage. Depth of water levels that will drown gophers will also cause crop loss of stands.

Additional Gopher Information:

UC Davis

Colorado State University

Gopher Treatment with PERC:

• Old mounds should be harrowed or otherwise reduced prior to treatment.
• The first treatment can reduce gopher populations by 66 percent or more.
• Population reduction of 95 percent can be achieved with two or three additional treatments after new mounds have surfaced.
• Gophers will reinvade a field and occupy old burrows.
• Maintaining clean gopher-free field borders can limit re-infestation.
• Light to moderate gopher infestations can be treated at a rate of 3 to 8 acres an hour.

Quick Ground Squirrel Facts:

• Live in colonies with several ground squirrels per burrow system.
• Holes are kept open.
• Ground squirrels hibernate in the winter, with males surfacing a couple of weeks earlier than the females, usually in February.
• Ground squirrel season extends from February till the food supply is exhausted, usually into August or September.
• They will usually have one litter a year-numbering from 4 to 10.
• They eat green surface foliage and will denude the immediate area around their burrow openings.
• They will forage up to 100′ from their burrow opening.
• The Belding ground squirrel can multiply at a very rapid rate and can exceed 100 rodents per acre.
• Holes can be part of a huge mound or partially hidden with no mound.
• Mounds can be several feet in diameter, over 12″ high, and packed very hard with squirrel traffic.
• Main holes can be 12″ in diameter at the opening and burrow several feet deep.
• Different holes and burrows within a colony may or may not be connected.

Additional Ground Squirrel Information:

UC Davis

California Ground Squirrel Info

Colorado State University

Animal Diversity Web

Ground Squirrel Treatment with PERC:

• Old mounds should be harrowed or otherwise reduced prior to treatment.
• Populations can be reduced by 70 percent or more from the first treatment.
• Two or three subsequent treatments can reduce populations by 95 percent.
• All active live holes must be treated and sealed with dirt.
• Only fresh active open holes need to be treated a second and third time.
• Treating ground squirrels in hibernation is not successful.
• Old infestations are difficult to treat due to the huge burrow complexes.
• The economic viability of treatment has to be determined by the farmer/rancher.
• New infestations can be totally eliminated with PERC treatments.

Quick Mole Facts:

• Solitary, one mole to the burrow system.
• Insectivores-moles eat worms, grubs, etc.
• Damage crops and turf by uprooting plants.
• Mounds and raised burrow areas can cause machinery damage and are unsightly in landscaping.
• Build two-tiered burrow systems. A subsurface burrow is used for feeding, and a lower burrow, laterals, from six to twelve inches deep, is used to connect feeding burrows and waste dirt mounds.
• Additional Mole Information:

Ohio State University

Mole Treatment with PERC:

• Successful treatment demands that laterals are probed and filled with carbon monoxide.
• Subsurface feeding burrows will not hold a high enough concentration of the fumigant gas to kill the mole.
• Treat fresh digging only. Moles reuse lateral burrows, but they are also continually digging new burrows.
• Persistence and multiple probes of the same burrow complex result in high levels of success.

Quick Vole (Field Mice) Facts:

• The names vole and field mice are used for basically the same mouse. Different locals use either one or the other or both (my experience).
• Voles live in colonies and can explode to very dense populations under favorable conditions.
• They eat green surface vegetation (for the most part) and can eliminate any growth within a colony.
• They have multiple holes within the colony that are kept open and may or may not be connected underground.
• Voles or field mice will establish new colonies, and under favorable conditions, adjacent colonies will expand till they overlap.

Additional Vole (Meadow Mice or Field Mice) Information:

UC Davis

University of Nebraska Vole Handbook

Vole (Meadow Mice or Field Mice) Treatment with PERC:

• Though multi-acreage treatment has not been done, individual colony treatment has proven successful.
• Voles are very susceptible to carbon monoxide.
• As many holes as possible within a colony should be fumigated at the same time if possible.
• Holes do not need to be sealed off. The sensitivity of the animal to CO and its heavier-than-air property works in the applicator's favor.
  Prairie dogs, gophers, ground squirrels, moles, and voles Burrowing rodents cause major damage to the land.

Pressurized Carbon Monoxide helps control destructive pests.