Rising temperatures in NWO risk spreading more disease to people and animals, experts say

Thunder Bay's unseasonably warm winter could lead to more disease among animals and humans, according to two experts who track wildlife and vector-borne diseases in the region.

Lakehead University Associate Professor Brian McLaren said animals such as squirrels and skunks have already become active in the city, and longer periods of activity lead to more disease-spread.

"I think with skunks, they're one of the top carriers of rabies," McLaren said. 

Chronic wasting disease, which affects deer, and lyme disease are also on the rise, he added. 

The coordinator of the vector-borne disease surveillance program with the Thunder Bay District Health Unit said 2024 could be a "bumper tick year," leading to more cases of lyme disease.

Ticks spotted in the centre of Thunder Bay

"There's been really only one cold snap, and [ticks] have to be at below minus 20 for a couple or three days to really be affected," Deacon said. 

"So I think there's going to be a fairly decent survival rate."

Ticks shelter under leaf litter on the ground, and snow cover helps keep them warm, he added. 

But the temperature has been so warm that the lack of snow is unlikely to make much of a difference to their populations. 

While many people know to check themselves for ticks if they've been out in the bush or in tall grass, Deacon said birds can carry ticks anywhere. 

"I do live right in the middle of the city, and our cat came in with a black legged tick on her ear two years ago," he said. "You really do have to be aware and take precautions."

Ticks have a variety of natural predators in the region, Deacon said, but nothing that is likely to put a dent in their number.

"I hope they never actually get to the level where we have predators that are focusing solely on the ticks," he said.

McLaren said it's impossible to know all of the ways that the warm temperatures will affect disease spread or how it might impact the ecosystem in other ways.

Some animals might find themselves becoming active before their food sources are available, he said.

That's particularly true of birds, which often migrate based on daylight changes, while the insects they eat often emerge due to hormonal signals.

Skunks too may not be able to locate the worms insects and frogs they often feed on, and that may lead them farther into residential neighbourhoods looking for garbage.

Bears, McLaren said, would likely not leave their dens any earlier than usual as their hibernation patterns are governed by hormones, not air temperatures.