Featured Pest: Trapping Rodents in the Pasture or Backyard
2018 Fallby Tim Fine
MSU Extension Agriculture Agent in Richland County
Managing a pasture for optimal forage production encompasses a variety of different management techniques. Plant establishment, stocking rates, fertilization, water, and fencing are some of the decisions that must be made in order to ensure that a given pasture is productive. Managing rodents in a pasture is another factor that must be considered and often does not get addressed until the problem becomes almost too large to manage.
Vertebrate pests, mainly pocket gophers, ground squirrels, and prairie dogs do more than just cause dead patches of forage in a pasture. Livestock and other animals have been known to break their legs when accidentally stepping into their holes and trying to drive haying equipment across the holes does not make for a pleasant ride.
When dealing with vertebrate pests, whether in open range or in the backyard, it is important to keep in mind that the primary reason the pest is there is because these animals need food, water, and shelter to survive. And since your pasture/backyard has these amenities, you may be dealing with these pests as long as you own or lease the land. Do not feel discouraged; there are options for control. Moles are absent from this article because moles do not exist in Montana.
Due to space limitations, this article will only focus on trapping as a means of controlling these rodents. It should be mentioned that trapping is only one form of control and there are other options. Regardless of the option chosen, careful research should be done to determine if the technique will actually work. There are several types of baits and gadgets available for purchase, but not all of them will achieve the desired outcome. For a more complete list of exclusion techniques, visit http://agr.mt.gov/Topics/Vertebrate-Pests. Here you will find research-based factsheets focused on identification and control of Montana’s vertebrate pests.
Trapping is generally considered the most effective way to control a vertebrate pest. Baits and fumigants work, though unlike trapping, these methods generally kill the rodent in the burrow and make it more difficult to ensure the desired outcome. Since the pests are different in their habits and biology, there isn’t one product that works for all of them.
Pocket gophers are probably the most common pasture pest. The easiest way to see a pocket gopher problem is to look at the mounds of soil left by the burrowing rodents. Pocket gopher mounds will be fan shaped and they will not (typically) have an opening. In fact, an easy way to tell whether or not a pocket gopher mound is active is to dig into the mound and leave it open. The pocket gopher will come back and close the mound as a way to prevent predation.
There are a few different types of pocket gopher traps available, but they essentially all work the same. To properly set traps, some excavation of the pocket gopher’s burrow must be done and trap(s) should be secured in the burrow with a wire coming from the end of the trap to a stake located outside of the burrow. The stake allows for easier trap locating, as well as ensures that if the animal is only partially snared, it does not take off with the trap. A single trap can be placed lateral to the gopher’s tunnel or with a little more excavation, two traps can be placed in opposite directions in the main tunnel.
Prairie dogs are another problematic pest in pastures and similar to pocket gophers, will leave mounds of soil on the surface. Unlike pocket gopher mounds, prairie dog mounds have openings in them. As such, setting a trap and capturing prairie dogs is somewhat easier. For prairie dogs, a body-gripping trap, such as the conibear #55 or #110 can be set directly over the opening of the burrow entrance. As with the trapping for pocket gophers, ensure that the trap is staked so that it is easier to locate and to prevent it from being dragged off. It should be noted that trapping prairie dogs is generally not recommended for areas larger than 10 acres. This is simply because this method of removal is time intensive and traps need to be checked at least daily.
The Richardson ground squirrel, Columbian ground squirrel, and Thirteen-lined ground squirrel all call Montana home. While they differ biologically, they do have similar characteristics and can be trapped using the same techniques. For ground squirrels, squeeze-type traps, choker-style traps, and baited rat traps all work for control. As with the others, traps should be anchored into the soil and can be placed near or at the opening of the burrow. If rat traps are used, they should be placed inside protective boxes with 2-inch wide holes to prevent non-target animals from being enticed by the bait. If there are several non-target animals in the area, cage or box traps may also be used. If using these types of traps, it is recommended that the animals caught be euthanized. Translocation is not recommended, and in some instances is illegal.
It should be noted that setting and releasing traps is a potentially dangerous task. Care should be taken when setting, placing, and removing animals from a trap. It is also important to keep in mind that there are laws and regulations for rodent removal. For more information on trapping, other pest control options, and laws and regulations, visit the Montana Department of Agriculture’s website at http://agr.mt.gov/Topics/Vertebrate-Pests.