Ground squirrels are also a pest to farmers because they destroy pasture and crops, which can amount to tens of thousands in losses. The holes also destroy the surface of fields, which in turn damages machinery.Supplied
Last fall, Kevin Wrista found his purebred bull on the ground with a broken leg. He scanned the surrounding area and saw a hole 15 centimetres wide: a badger den.
Mr. Wrista, whose ranch is in Elk Point, Alta., about 200 kilometres east of Edmonton, pulled out his rifle and shot the bull dead. He had no choice; half-tonne bulls do not recover from broken legs.
The bull was a yearling purebred. It would have fetched at least $1,900 at market, but its breeding potential made it much more valuable. This was a loss Mr. Wrista could hardly afford, especially given the two years of drought and hay shortage he and other ranchers have endured.
Ranchers on the Prairies are worried that broken legs are only set to increase in the coming years as the federal government phases out strychnine. Ranchers and farmers use the toxic chemical to kill Richardson’s ground squirrels – the prey that draws badgers and their leg-breaking holes – but Ottawa is banning its use to protect animals that eat the poisoned rodents.
“If you don’t poison the gophers, a pasture turns into a minefield,” said Mr. Wrista. “Without strychnine, it’s not a case of if my livestock break their legs, but when.” (A Richardson’s ground squirrel is a different animal than a gopher but they are often used interchangeably.)
The ground squirrel’s greatest predator is the badger, and the longer the squirrels live, the more leg-breaking badger holes scatter the pastures.
Ground squirrels are also a pest to farmers because they destroy pasture and crops, which can amount to tens of thousands of dollars in losses. The holes also destroy the surface of fields, which in turn damages machinery.
The easiest, fastest and cheapest way to control ground squirrels is with 2-per-cent liquid strychnine concentrate – a product farmers mix with grain and put down holes. The ground squirrels typically die immediately.
However, as of March 4, 2023, farmers will no longer be able to use strychnine for ground squirrel control. The phase-out began in 2020 when Health Canada Pest Management Regulatory Agency, or PMRA, deregistered the product. March 4 was the last date municipal and county governments were permitted to sell the product.
The agency announced the ban in 2020 after looking at the issue for two years. Industry groups and provincial governments in Alberta and Saskatchewan objected, arguing that strychnine is the only effective tool to control the squirrels and that it can be used in a way that mitigates its environmental impact.
The agency has said the deregulation is based on five field studies conducted between 2001 and 2019 that showed strychnine can poison other animals in the ecosystem, specifically when these “non-target species” eat the poisoned ground squirrel carcasses. Of particular concern is the effect on endangered species such as the swift fox and burrowing owl.
PMRA also said there was a lack of practical mitigation measures to protect non-target species.
“PMRA found that strychnine for the control of Richardson’s ground squirrels did not meet current standards for environmental protection,” said PMRA in an e-mailed statement. The agency declined an interview request.
PMRA is encouraging farmers to instead use other chemicals, such as aluminum phosphide or RoCon, a white mustard seed powder.
But farmers and ranchers like Mr. Wrista are not convinced that these products work. For example, for a ground squirrel to die from RoCon they have to be poisoned four times. This requires more of a farmer’s labour and time, putting them at a disadvantage in a fight against a rodent that births litters of 10.
Non-chemical options include ramping up natural predation, a technique used by rancher Carter Bezan in Southey, Sask. In problem areas, Mr. Bezan constructs holes for raptors to nest in and he does not shoot coyotes. Both prey on the squirrels. When he has the chance, he also shoots the rodents.
“Predation is the main reason we have no gopher problem,” said Mr. Bezan. “It’s a different technique but it works for us.”
However, Mr. Bezan knows that this is not the solution for all ranchers or farmers. Often, the raptors and coyotes cannot keep up with a ground squirrel infestation. Mr. Bezan said he is lucky to have a small-scale operation where less-intensive measures work.
Not all farmers are so fortunate.
“In an average year, two-thirds of Alberta and Saskatchewan farmers depend on strychnine,” said Roy Orb, president of the Saskatchewan Association of Rural Municipalities. “Especially in a drought year like this when outbreaks are more pervasive. Nothing else is as effective.”
Mr. Orb also questions the research behind the decision to deregulate. He points out that the most recent study on strychnine – funded by Saskatchewan’s Ministry of Agriculture and published in 2019 – did not support the deregulation of the product. Accordingly, the study found that only three non-target animals – field mice – were poisoned.
James Tansey, a specialist in insect and pest management for the Saskatchewan Ministry of Agriculture, was the author of the 2019 report. He seconds Mr. Orb’s statements.
“The government of Saskatchewan’s position remains that, when used according to the label, strychnine is the most efficient and effective control measure for Richardson’s ground squirrels,” said Mr. Tansey. “It also has limited environmental effects.”
Mr. Tansey said research on the effects of strychnine is limited and dated, and it does not conclusively prove that the product is bad for the environment. This is because the label instructions specify that farmers should put the poison down the hole and be sure to safely discard any poisoned rodents that might leave their holes.
“Strychnine is a very potent toxicant,” said Mr. Tansey. “And there is always the potential for abuse. But from my knowledge, ranchers and farmers use it judiciously. To my knowledge, the label is the law.”
Mr. Wrista agrees. He and the other ranchers he knows always pick up their carcasses.
“I do my due diligence, I have respect and I do what the label tells me to do,” Mr. Wrista said. “Most respectable farmers do. We all own dogs, we don’t want to poison our own.”
The Canadian Cattlemen’s Association fought the deregulation of strychnine based on these objections, and procured the signatures of 1,400 rural delegates in support. However, they were shut down. PMRA addresses these concerns in a statement on its website, arguing that the decision was based on other studies that predate the 2019 research, such as a 2002 study that pointed to strychnine poisoning in non-target animals. They also argue that numbers are underestimated because scavengers often remove the poisoned carcasses from fields, and because those conducting the survey might miss a few dead animals.
Regardless, the PMRA’s decision will hurt ranchers, they say.
“There’s gonna be a lot of economic hurt,” said Mr. Orb. “Quite a few ranchers are on the verge of going out of business; they’ve been short on feed and water and have had to sell their stock, hoping for better weather. We’d hope that PMRA would see this.”
To try to combat the costs, Saskatchewan’s Ministry of Agriculture and Mr. Tansey are turning their attention to the legal, regulated alternatives to strychnine: RoCon and zinc phosphate. They have begun a study that will compare the two techniques in a ground squirrel-infested area outside Regina.
But Mr. Wrista is not hopeful about the alternatives. He will be turning to trapping, a time-consuming and expensive technique that often fails to keep up.
Mr. Wrista is frustrated and nervous about next year, but he remains confident that ranchers and farmers across Alberta and Saskatchewan will find a solution to the problem.
“All farmers are very innovative,” he said. “One way or another, we’ll find a way.”
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Editor’s note: A previous version of this story identified Ray Orb as president of the Canadian Cattlemen’s Association. In fact, he is president of the Saskatchewan Association of Rural Municipalities.