Moose-killing ticks draw close attention of researchers

Winter ticks threatening the moose of New Brunswick and southern Quebec are the subject of a five-year study now underway.

The deadly ticks are showing up in greater numbers in the two research areas, according to Prof. Steeve Côté of Laval University, the lead researcher on the project.

Unlike the blacklegged tick, which presents its own set of health hazards, the winter tick does not carry diseases such as Lyme.

But the ticks can be fatal to moose, infesting a single animal by the thousands.

In southern Maine and New Hampshire, the recorded mortality rate for moose calves was as high as 75 per cent in areas with dense winter tick populations, said a news release from J.D. Irving Ltd.

The huge impact on survival rates is supported by research in Western Canada, where there's also an abundance of the ticks.

JDI has signed on to be a major sponsor of the project, which is also backed by the universities of Laval, Montreal and New Brunswick as well as the two provincial governments.

Catch and release

The study will use a catch-and-release strategy to track moose and gather data to assess the health of moose in areas where winter ticks are abundant.

Researchers will examine why moose are so attractive to the ticks, and the role climate change plays in shifting tick behaviours. 

Côté said the winter tick is in a larval stage when it climbs onto vegetation in the fall and awaits big game to approach.

Once on a moose, the larvae will feed on blood meals throughout the winter and they grow into adults.

Côté said the female tick is as large as a fingernail by the time it is ready to lay eggs in the spring.

And it's not just a few ticks at a time that feed off the moose.

"They can get to very large numbers, like several thousand ticks on one animal," Côté told Information Morning Saint John. 

As a moose suffers significant blood loss, Côté said, the animal is also at risk of exposure during the cold months.

The moose will attempt to scratch away the ticks by rubbing against trees, removing large patches of hair.

Côté said the researchers will treat half the moose they catch and release.

"With that experiment, we could isolate the impact of ticks only, not of the other parasites or any other reason," he said.

"So, we will know, for sure, what's the impact of the winter ticks without the other factors."

Celebrity vet on board

The data will also help researchers learn more about the ticks' habits and habitats — elements that appear to be evolving with climate change.

"Based on these results, we'll be better able to modify, for instance, forest management so that we can cut blocks in places that are more favourable for ticks so that we can decrease their abundance," Côté said.

Dr. Michelle Oakley, star of National Geographic's Yukon Vet as well as NBC's Wilderness Vet, will be assisting the study to ensure the animals are cared for.

"We're all concerned about winter ticks, and we're concerned about it all the way up to the Yukon — we have found winter ticks there," Oakley said in the JDI release.

"With climate change, it's definitely changing the lifecycle of parasites like ticks, and moose are very susceptible to them."

Côté said the first captures occurred this winter and will continue into the next decade.