EUSTIS – Sometimes the smallest can overpower the largest. That’s the case when winter ticks contribute to the demise of moose.

“When these small organisms . . . parasites . . . these very small critters congregate in large numbers on the back of a moose, it can have devastating effects,” said Lee Kantar, deer and moose biologist for the Maine Department of Inland Fisheries.

How much influence winter ticks have on the mortality of moose is a question that has a University of Maine senior counting the number of ticks on freshly killed moose bodies.

Katelyn Andrle, 21, of Clifton will join other state biologists at the weigh station in Eustis this week of moose hunting. While biologists check basic biological information, Andrle will check four 10- by 10-centimeter locations on the moose and count the ticks.

As part of an independent study course, the Orono wildlife ecology major contacted Kantar looking for a project. The state has counted tick loads since 2006, but there wasn’t the staff to do it this year, he said.

“Essentially, we want to know what the tick load looks like on the moose. The only way to do that is through hunter-harvested moose. It’s not a great time to do it but it’s the best we have,” Kantar said. “The moose can’t be dead for too long or the ticks drop off as the carcass cools.”

One winter is the life cycle for the winter tick, so tick larvae spend fall months looking for a host. Ticks move up the stems of brush waiting for the moose so they can climb aboard and have a new home for the winter, he said.

A large infestation of winter ticks can drain a lot of blood from a moose, exposing it to anemia, infections and sometimes harming body conditions to the point of causing hypothermia, he said.

March and April, when the ticks take their last blood meal, can become a stressful time for moose, especially since it’s harder then for them to find food, he said.

“The toll of up to 50,000 ticks can add up. More mature animals can withstand it better, but the ticks can take half the blood of a calf. Time spent grooming and trying to get the ticks off means (they’re) not foraging for food,” he said.

Moose will rub against trees trying to get rid of the ticks sometimes creating extensive hair loss that makes them look whitish or gray, he said.

Andrle will also study weather data and plans to write a proposal for collecting more data. Warmer autumns and less snow in the spring have an effect on winter tick populations, she said.

A very cold fall reduces tick activity. If there is still snow when the tick drops off the moose in March and April, it will die in the snow. Without snow, the ticks will probably do OK, he said.

Use of weather data will help predict winter tick loads on moose for the following year. The information could help with predictions on moose mortality rates, she said.

The work sounds gross, and Andrle has never done it before, but is taking it in stride.

“As long as they are not crawling on me,” she said. She’s also happy to have an independent study that will contribute to something, “we’ll actually be able to use this information,” she added.

While small, the winter tick is larger than the deer tick that can carry Lyme disease. The winter tick does well on larger hosts such as moose but any animal, including humans, at the right height of brush can be a target, he said.