Quebec’s moose population may be growing steadily, but it’s facing a new threat: a parasite called the winter tick.

The insect lodges itself in the animal’s fur in the fall and holds on through the winter, feeding off the animal’s blood. While many end up recovering, a large number of moose end up dying from exhaustion and weakness.

“It’s certain that there are moose who are strongly affected by the tick, and so the death rate remains a factor we have to address very quickly to be able to better evaluate the effect of these parasites on the moose populations,” said Éric Jaccard, a biologist with the Ministry of Forests, Wildlife and Parks.

A moose suffering from exhaustion due to winter ticks. (Découverte/Radio-Canada)

The ministry confirmed the ticks as the cause of death in a number of moose.

According to some of the first data collected, three-quarters of the moose surveyed south of the 50th parallel were carrying winter ticks. Below the St. Lawrence River, that percentage climbs to 93 per cent.

The numbers are high, but it is not yet known at what point the parasites begin seriously affecting the health of the moose.

However, looking at the state of New Hampshire — where the moose population has diminished by half over the past 15 years — is a cause for concern.

Kristine Rines, a biologist working for the state’s fish and game department, has been tracking moose populations in New Hampshire.

“The last study showed us that winter ticks is really the major mortality source that we have for moose. But since then, even though we have these known mortality rates, even though we have reduced the permits using these known mortality rates, the populations have continued to go down,” Rines said.

Several experts hypothesize the ticks are moving farther north as a result of global warming.

Winter ticks living off a moose's ear in southern Quebec. (Serge Simoneau/Linda Brochu)

No treatment

There aren't many treatment options available short of putting giant flea collars on the wild animals.

Crossbow hunter Serge Simoneau has had a controlled harvesting zone near the Quebec-Maine border for over 20 years where moose regularly come to eat his salt.

The female winter tick is much larger than the male. (Découverte/Radio-Canada)

He began noticing moose carrying ticks about 10 years ago, and says the numbers have only increased — both the number of moose infected with ticks, and the number of ticks they are carrying.

According to Simoneau, who alerted the ministry in 2007, some moose had tens of thousands of ticks on their bodies.

The decreasing moose population spurred Simoneau to ask other hunters not to kill female moose.

He decided to illustrate the epidemic by taking pictures of moose who came near his salt lick. The results were staggering — animals are seen in poor condition, with open wounds and tumours, and showing signs of exhaustion.

The life cycle of a winter tick. (Découverte/Radio-Canada)

Watch the full TV story on Radio-Canada's Découverte program on Sunday at 6:30 p.m.