By Harry Brook
A lot of people are noticing the gophers running around now. Is this the right time to be trying to control the gophers? Not really. They are not even really gophers. They are Richardson ground squirrels and they have been a pest in our fields for a very long time.
Perhaps you are not aware, but the best time to control these squirrels is early in the spring, before they mate, before the grass starts to grow. What we are seeing now are the babies born this spring. The males go back into hibernation in June and the females go back into hibernation in early July.
Richardson ground squirrels (RGS) tend to be a problem in drought years. The crops grow poorly and these squirrels eat grass and crop. If there isn’t much grazing on pasture, they move into the annual crop. A bad infestation can clean off several acres in a field. The RGS are mostly vegetarian and will eat anything green and growing. If you are going to use poison to try to control them, you need to do it when there is little else for them to eat. March and April are excellent times for gopher control as their regular food source has not started growing and they will take poisoned bait.
The problem with strychnine is that poisoned RGS can, in turn, poison any animal that eats that carcass. This causes deaths of other, non-target animals. Because of the unintended consequences of killing birds and predators, the time left to us to use strychnine for gopher control is rapidly coming to an end. The federal government, through the Pest Management Regulatory Agency, registers pest products and they have decided the registration for the use of strychnine for RGS control will not be renewed. It will expire on March 4, 2023. Sales can be made until March 4, 2022. The PMRA reviews pesticide registrations every 10 years and research with strychnine and RGS have shown there is far too many non-target animals getting poisoned from eating dead squirrels. This includes any scavenging coyotes or birds and hawks.
There are ways to manipulate the environment to reduce the impact of RGS. This includes leaving adequate grass length in the pastures to prevent RGS from seeing when predators approach. Some have built hawk roosting poles to allow hawks to keep an eye on an area. Swainson’s hawk’s primary food source is RGS. Other poisons that have been used in the past but they tend to be rather ineffective. Badgers are effective biological control but the holes and damage just get larger.
As we see the end of use for strychnine to control Richardson ground squirrels, maybe now is the time to do some research into other, less destructive ways of reducing damage from these prolific rodents.