By Richard Wilkins, Provincial Specialist – Pesticide Regulatory, Regina
The Richardson's ground squirrel (RGS), commonly known as the gopher, is a perennial problem for producers. If you have recently experienced or are experiencing control issues of these pesky little rodents, you will likely have the same problems again next year.
Annual control is necessary to prevent a build-up of the gopher population and to avoid the population explosion that can result when environmental conditions favour the pest, such as successive dry years and/or mild winters.
The best method to control the RGS population is to limit its reproduction. Rodenticides are the most effective method of control, but proper timing of bait placement is very important. Early spring is the best time for baiting, as the newly emerged gophers are searching for food. During the summer, the rodent's favourite food source is lush green vegetation. Research has shown that once the fields green up, the gophers tend to avoid the bait in favour of the lush, green vegetation, meaning summer is not the best time to be initiating chemical control
Integrated pest management (IPM) is a strategy to attain sustainable, long-term pest control. IPM uses all viable options, both chemical and non-chemical, to keep pest damage below the levels of economic loss while reducing negative impacts on the environment. Some natural factors that affect RGS populations, like weather conditions are beyond the control of producers. Not all options will work in all or for all farming operations. However, it is important to consider other options aside from rodenticides as part of long-term management of RGS to prevent outbreak situations
An IPM program for RGS includes physical or mechanical control measures, cultural or historical control measures, biological control measures, rodenticides and chemical control options.
Physical or mechanical control measures include trapping (e.g. guillotine-type traps) and something like RoCon. Trapping can be an effective tool, but may be best suited for smaller areas with high populations of RGS. RoCon is a foam product that is injected in RGS burrows to suffocate the rodents.
Cultural or historical control measures include keeping vegetative height above 15 cm (six inches) and shooting/hunting.
Biological control measures include establishing and maintaining predator habitat like installing raptor platforms or nesting boxes for predatory birds or maintaining native grass lands. Predation accounts for approximately 30 per cent of RGS control. Foxes, badgers, weasels and coyotes as well as raptors (hawks) and bull snakes all feed on RGS and are important in maintaining a normal population level of RGS. Providing predator habitat keeps them in the area and actively hunting RGS.
For more information on Richardson's ground squirrels and Integrated Pest Management, contact the Agriculture Knowledge Centre at 1-866-457-2377.