Ontario study tracks moose decline as population drops up to 50 percent in north

THUNDER BAY · The moose population in Ontario has dropped by about 20 percent since the early 2000s, with declines of up to 50 percent in parts of the north, and a provincial ministry is trying to determine why. Ministry of Natural Resources and Forestry research scientist Nick Luymes recently presented findings from a multi-year research project in Wildlife Management Unit 13 near Thunder Bay. The project, which began in 2024, examines factors like predator-prey dynamics, disease, calf survival, road impacts and forestry activities. Despite significant reductions in hunting tags over the years, moose numbers have largely failed to increase in nearly two decades, according to Luymes.

"We want to get an understanding of what makes these limiting factors important so we can target that context in our manipulative experiments," Luymes said. "We want any of our findings to be useful for other parts of the province and what's driving those factors." In the last two years, ministry staff have captured and collared more than 200 moose in the Thunder Bay area with GPS and video tracking to monitor movements and behaviour. "At capture, we get a lot of data such as pregnancy status, health, parasite load, condition of their body and information on genetics," Luymes said.

Luymes noted that much of the decline can be attributed to low calf survival, with only one third making it through their first year due to active predators like wolves and black bears. The team determined the approximate annual survival rate for adult cows is 95 percent and 70 percent for adult bulls. To date, 36 of the collared moose in the study area have died. "We get alerts for when a moose might be dead. If they are, we can collect samples and do investigations at the site to understand why they died," Luymes said.

READ MORE: Record European heat killed over 50,000 people this summer, study finds

READ MORE: Scientists discover previously unknown North Atlantic right whale calf

Vehicle collisions and hunting were the most common causes of mortality for adult males, while predation was the most common for calves and yearlings older than eight months. For adult females, "unknown health problems" topped the list. "We're hoping to get better confirmation on what the specific causes are," Luymes said. "We have bodily samples submitted to labs that will do more formal analyses on what's causing those deaths."

Climate change and forestry practices cited

Dave Pearce, a senior forest conservation manager with the conservation group Wildlands League, said while predators have an impact, they should not receive all the blame. "It's easy to say they're driving things, so reduce the predator population," he said. "But that's kind of a Band-Aid that doesn't really address the core fundamental issues." Pearce said a big contributor is climate change, pointing to rising and above seasonal temperatures. "Especially in the spring, we've been having sudden onset of summer-like heat and moose can get hyperthermic and overheat very quickly," he explained. "Heat-stressed animals won't move around and feed as much, and that doesn't only impact the animal but its offspring too."

Pearce noted a warming climate benefits white-tailed deer, and if their numbers rise, more predators could flock to that habitat, ultimately impacting moose. He also raised the issue of winter ticks that feed heavily on moose, though Luymes explained the ministry is not noticing significant concerns about ticks in its study area. Hunter Jeremy Coulis, from Batchewana First Nation and Sault Ste. Marie, said the sport has become much more challenging. On a recent week-long trip north of Aubrey Falls, he and seven friends saw four moose. The previous year, the same group saw only one moose across 10 days of hunting.

"It's definitely harder now," Coulis said. "You can spend days and days out there, but the moose just aren't there. When you see one, it's actually kind of a shock and a surprise nowadays." Coulis expressed concern over forestry companies that spray forests with herbicides to kill broadleaf vegetation, which competes with coniferous trees harvested for lumber. "Quebec has proven that their moose population has rebounded substantially since they stopped spraying," Coulis said. "But Ontario has no interest in stopping the spray."

With files from CBC News