Poison in the Prairies: The Hidden Costs of Poisoning Ground Squirrels

Richardson’s ground squirrels in their natural habitat: open, short-grass prairie. They are often casually called gophers or prairie dogs, though those names actually refer to different rodent species.

When Richardson’s ground squirrel populations boom, they are impossible to ignore. They clip crops, damage pasture, create holes that can injure livestock, and place even more pressure on producers already dealing with drought, rising costs, and uncertainty. The frustration is real, and it is easy to see why, in those moments, the conversation turns to poisoning.

However, ground squirrels are more than a nuisance; they are woven into the prairie food web. Coyotes rely on them. Hawks and owls hunt them. Badgers dig them out of their burrows. Even their tunnelling changes the land, reshaping soil and influencing how water moves through it. Once you see them that way, poisoning stops looking like a simple one-species solution; it becomes a choice with consequences that can ripple through the whole grassland.

Poison doesn’t stay put 

A lot of the public discussion around prairie ground squirrel poisoning assumes that if poisoned bait goes down a burrow, the risk stays there, too. The research says otherwise. In its 2020 re-evaluation of strychnine for Richardson’s ground squirrel control, Health Canada’s Pest Management Regulatory Agency concluded that the environmental risks to non-target wildlife, including species at risk, were unacceptable (Health Canada, PMRA, 2020). The same review noted that poisoned carcasses still turned up on the surface, that bait could be ejected from burrows, and that measures such as placing bait deeper or covering burrow entrances did not reliably prevent exposure to other wildlife (Health Canada, PMRA, 2020).

Richardson’s ground squirrel burrows are not neat little one-door systems. Instead, they are extensive tunnel networks, and each squirrel can use multiple entrances. Badgers make the problem of containment even more obvious. In southern Alberta, badgers are documented to routinely hunt Richardson’s ground squirrels underground by excavating burrow systems, sometimes taking hibernating squirrels below the surface and sometimes intercepting animals moving through tunnel networks (Michener, 2004). Coyotes work these colonies too, and a recent Saskatchewan study found that Richardson’s ground squirrels were the most common prey item recorded in the coyotes studied there (Jackson et al., 2026). 

So even if some poisoned squirrels die below ground, that does not seal the risk away. Sick animals can emerge. Carcasses can appear on the surface. Burrows can be dug into. Scavengers can arrive. In an open prairie system, poison does not respect the tidy boundary people often imagine between target species and everything else.

American badgers are one of Richardson’s ground squirrels’ most effective natural predators, digging them out from deep within their burrows.

Predators are doing the work already

One of the clearest lessons from ecology is that when natural predator communities are weakened, prey species often have more room to surge. That does not mean predators are the only factor shaping Richardson’s ground squirrel numbers, but it does mean they are part of the system that helps keep those numbers in check. Alberta’s own guidance notes that predation plays a significant role in natural population control for Richardson’s ground squirrels, and broader ecological research shows that removing top predators can trigger prey irruptions and food-web imbalances. In practical terms, that means protecting hawks, owls, coyotes, badgers, and other native predators is not just good conservation, it is good common sense. If we want fewer boom-and-bust cycles in prey species like Richardson’s ground squirrels, it behooves us to keep their predators intact and give them the habitat they need to do the work they have always done.

Badgers matter here in a special way because they can access prey underground. In other parts of Canada, badger populations are already a conservation concern, and the prairie picture has not always been backed by strong local data. Older national status material noted that Alberta had treated badgers as data deficient and that Saskatchewan lacked provincial rankings at the time, which is not proof of a hidden crisis but certainly is a reason to be careful about adding a known predator exposure pathway into the system (COSEWIC, 2012; Environment and Climate Change Canada, 2023). 

Raptors matter too. Research across Canada and North America has found residuals of poisons in many species of birds of prey, including hawks, falcons, and owls (Elliott et al., 2016; Elliott et al., 2022; Health Canada, Pest Management Regulatory Agency, 2017; Murray & Cox, 2023). Federal species information for Ferruginous Hawks, an endangered species under Alberta's Wildlife Act, notes that their numbers fluctuate with Richardson’s ground squirrels and warns that poisoning ground squirrels can adversely affect some local hawk populations (Government of Canada, 2019).

Coyotes are often treated only as a conflict species, but they are also free labour from an agricultural point of view. Every ground squirrel taken by a coyote, a badger, an owl, or a hawk is one less animal clipping forage, enlarging a colony, or producing another litter. If heavy poison use suppresses those predators or exposes them to harm, producers can end up weakening the very control system that costs them the least to maintain.

A coyote leaps through the frosty grass. These canids are often seen as a pest species, but they do important work controlling the populations of rodents like Richardson's ground squirrels.

What the poisons actually do

Strychnine deserves special attention because it is often talked about as though it is simply the fast option. It is true that strychnine usually acts much faster than anticoagulant rodenticides, but faster does not mean humane. Strychnine poisoning is an acute neurologic emergency that can bring on severe muscle spasms, seizures, and respiratory failure within minutes to a couple of hours. From an animal-welfare standpoint, that is one reason strychnine has drawn so much criticism over the years. Just as troubling, the suffering does not stop with the ground squirrels. Predators and scavengers that consume poisoned Richardson’s ground squirrels can also be poisoned, meaning the same toxin can move through the food web and cause intense pain and distress far beyond the original target (Proulx, 2011).

Health Canada cancelled strychnine for Richardson’s ground squirrel control in 2020 after concluding that the environmental risks were unacceptable, although a later time-limited emergency authorization reopened its use in Alberta and Saskatchewan with added restrictions, stewardship requirements, and monitoring conditions (Health Canada, 2026; Health Canada, PMRA, 2020). Whether one sees that reversal as necessary, temporary, or troubling, the ecological problem underneath it is the same: once poison enters a prey species that sits at the centre of the food web, it becomes very hard to keep the consequences confined to that one animal.

Anticoagulant rodenticides create a different problem. They usually act over days rather than hours, causing internal bleeding and prolonged illness. That longer timeline matters because it gives poisoned animals more time to move around, weaken in the open, or be caught by predators before they die. Reviews of anticoagulants have raised both welfare concerns and secondary-poisoning concerns for exactly that reason, and work from North America has shown widespread contamination of raptors with these compounds (Elliott et al., 2022; Fisher et al., 2019). So although strychnine and anticoagulants work differently, both can move ecological harm well beyond the intended target.

A Ferruginous Hawk released by Calgary Wildlife. This large bird of prey is listed as Endangered under the Alberta Wildlife Act

The overlooked benefits of ground squirrels

It is also worth remembering that Richardson’s ground squirrels are not ecologically empty animals. They do more than eat plants and act as prey species for other animals. Their digging changes the ground itself. In Manitoba, a study found that burrowing Richardson’s ground squirrels altered seedling assemblages by changing conditions on their mounds, including increasing bare ground and soil nitrate (Newediuk and Hare, 2020). In other words, they functioned as ecosystem engineers.

Studies have also found that small mammal burrows increased water infiltration into the soil, with more winter moisture moving into deeper soil near burrows (Laundré, 1993; Kinlaw, 1999). Burrows can act like macropores, helping water move downward instead of simply running off or evaporating near the surface. In a region where people are rightly worried about drought, soil moisture, and declining resilience, that is not a trivial point.

None of this means dense ground squirrel colonies are always good for agriculture. High numbers can absolutely reduce forage and damage land, but it does mean the animals are doing more than taking. They also contribute to aeration, water infiltration, nutrient movement, and the kind of patchy disturbance that shapes prairie plant communities. That is part of the picture, too.

A Richardson’s ground squirrel gathers grass for its burrow. These small mammals are important ecosystem engineers, creating complex underground burrow systems that shape the prairie around them.

The bigger prairie context

When conditions are dry, it is understandable that visible culprits get most of the blame. Ground squirrels are visible. Their holes are visible. Their feeding damage is visible. Climate change is not always visible in the same way, even when it is the bigger force shaping the situation. Canada’s climate assessments show that warming is increasing evaporation and transpiration and contributing to more frequent, more intense drought and soil-moisture deficits across the Prairies (Bush & Lemmen, 2019; Sauchyn et al., 2020). Agriculture and Agri-Food Canada makes a similar point: Canadian agriculture can expect more extreme weather, higher temperatures, and changes in precipitation that increase the risks of drought and other climate stressors (Agriculture and Agri-Food Canada, 2022).

A bad year for ground squirrels can hurt farmers and ranchers, but a warming climate changes the baseline for everything, including crops, forage, water, and the conditions that can favour pest surges in the first place. If the goal is long-term agricultural resilience, then the answer cannot just be to kill the most visible small animal on the landscape and hope the larger pressures take care of themselves.

Keeping prairie landscapes intact helps protect the open spaces, native grasses, and wildlife that depend on them.

The better long game

No one is denying that Richardson’s ground squirrels can pose real problems for producers, or that boom years demand a response. The question is not simply how fast numbers can be knocked back; it is what kind of prairie is left afterward. The prairie is already under strain from drought, heat, habitat loss, and fragmentation. In a system carrying that much pressure, the way we choose to manage one species matters.

Predator-friendly habitat, taller vegetation where possible, raptor platforms, nest boxes, and other integrated pest-management approaches may take more patience than pouring poison into burrows, but they offer something poison cannot: control that does not come at the expense of the prairie food web. Rather than contaminating the prey base and putting hawks, owls, coyotes, foxes, and badgers at risk, these approaches support the very animals that help keep ground squirrel numbers in check.

That is the real problem with relying on rodenticides; it is not that the people who use them are careless or cruel, but rather that poison is a blunt tool in a landscape built on relationships. Richardson’s ground squirrels are prey. Their predators are useful. Their burrows are complex. Their carcasses do not always stay hidden. Their digging reshapes soil and influences how water moves through the land. Once those facts are on the table, predator-first control stops sounding sentimental and starts sounding practical.

The goal should not just be fewer ground squirrels. It should be a prairie still capable of holding itself together under the weight of everything we are asking it to bear, and that means making choices that leave the prairie more resilient, not more fragile.

Support A Patient

For assistance with injured wildlife, please contact the Calgary Wildlife Rehabilitation Society at 403-214-1312.

Even the smallest prairie patients deserve expert, compassionate care. This Richardson’s ground squirrel is being examined by Calgary Wildlife after coming into rehabilitation.

References:

Agriculture and Agri-Food Canada. (2022). Agriculture and Agri-Food Canada’s strategic plan for science. Government of Canada.

Bush, E. and Lemmen, D.S., editors (2019): Canada’s Changing Climate Report; Government of Canada, Ottawa, ON. 444 p.

COSEWIC. (2012). COSEWIC assessment and status report on the American badger (Taxidea taxus) in Canada. Government of Canada.

Elliott, J. E., Rattner, B. A., Shore, R. F., & van den Brink, N. W. (2016). Paying the pipers: Mitigating the impact of anticoagulant rodenticides on predators and scavengers. BioScience, 66(5), 401–407. https://doi.org/10.1093/biosci/biw028

Elliott, J. E., Silverthorn, V., Hindmarch, S., Lee, S., Bowes, V., Redford, T., & Maisonneuve, F. (2022). Anticoagulant rodenticide contamination of terrestrial birds of prey from Western Canada: Patterns and trends, 1988–2018. Environmental Toxicology and Chemistry, 41(8), 1903–1917. https://doi.org/10.1002/etc.5361.

Fisher, P., Campbell, K. J., Howald, G. R., & Warburton, B. (2019). Anticoagulant rodenticides, islands, and animal welfare accountancy. Animals, 9(11), Article 919. https://doi.org/10.3390/ani9110919

Environment and Climate Change Canada. 2023. Recovery Strategy for the American Badger jeffersonii subspecies (Taxidea taxus jeffersonii) Western population and Eastern population in Canada. Species at Risk Act Recovery Strategy Series. Environment and Climate Change Canada, Ottawa. 2 parts, 32 pp. + 36 pp.

Government of Canada. (2019). Ferruginous Hawk (Buteo regalis). Bird status.

Health Canada, Pest Management Regulatory Agency. (2017). Questions and answers: Additional mitigation measures for rodenticides. Government of Canada.

Health Canada, Pest Management Regulatory Agency. (2020, March 4). Re-evaluation decision RVD2020-06: Strychnine. 

Health Canada. (2026, March 30). Statement from the Minister of Health and the Minister of Agriculture and Agri-Food on strychnine in Alberta and Saskatchewan.

Jackson, S. M., Miller, M. P., & Lingle, S. (2026). Pest or pest control? Coyote interactions with cattle and Richardson’s ground squirrels. Canadian Journal of Zoology, 104. https://doi.org/10.1139/cjz-2025-0074

Kinlaw, A. (1999). A review of burrowing by semi-fossorial vertebrates in arid environments. Journal of Arid Environments, 41(2), 127-145. https://doi.org/10.1006/jare.1998.0476.

Laundré, J. W. (1993). Effects of small mammal burrows on water infiltration in a cool desert environment. Oecologia, 94, 43–48. https://doi.org/10.1007/BF00317299

Maureen Murray, Elena C. Cox (2023). Active metabolite of the neurotoxic rodenticide bromethalin along with anticoagulant rodenticides detected in birds of prey in the northeastern United States. Environmental Pollution, Volume 333, 2023, 122076, ISSN 0269-7491.https://doi.org/10.1016/j.envpol.2023.122076

Michener, G. R. (2004). Hunting techniques and tool use by North American badgers preying on Richardson’s ground squirrels. Journal of Mammalogy, 85(5), 1019–1027. https://doi.org/10.1644/BNS-102

Newediuk, L. J., & Hare, J. F. (2020). Burrowing Richardson’s ground squirrels affect plant seedling assemblages via environmental but not seed bank changes. Current Zoology, 66(3), 219–226. https://doi.org/10.1093/cz/zoz047

Proulx, G. (2011). Field evidence of non-target and secondary poisoning by strychnine and chlorophacinone used to control Richardson’s ground squirrels in southwest Saskatchewan. In D. Danyluk (Ed.), Patterns of change: Proceedings of the 9th Prairie Conservation and Endangered Species Conference, February 25–27, 2010, Winnipeg, Manitoba (pp. 128–134). Critical Wildlife Habitat Program.

Sauchyn, D., Davidson, D., & Johnston, M. (2020). Prairie Provinces. In F. J. Warren, N. Lulham, & D. S. Lemmen (Eds.), Canada in a changing climate: Regional perspectives report. Government of Canada.