State biologists plan to begin capturing dozens of moose next week as part of the Maine Department of Inland Fisheries and Wildlife annual moose survival study.

Biologists working in conjunction with helicopter crews will start to capture and place radio collars on 130 moose on Monday, according to DIF&W spokesman Mark Latti. He said the effort should take no more than two weeks to complete.

The moose capture campaign will target populations in northern Aroostook County, western Maine, and a region to the north of Moosehead Lake in northern Somerset and Piscataquis counties.

Latti said in a statement Thursday that Maine’s moose population fluctuates due to many factors, including calf birth and adult survival rates. This year’s study, which will be led by state moose biologist Lee Kantar, will focus on causes of death.

The survival study, which began in 2014, has resulted in the capture of about 475 moose using helicopter-launched nets. Latti said that helicopters fly over areas where moose have been spotted and fire a net at the moose. Once the animal has become tangled in the netting, it typically falls to the ground.

That is when a crew of so-called “muggers” leap from the helicopter and tie the moose’s legs with a belt. The muggers place a blindfold over the moose’s eyes. In the process, the crew takes blood and fecal samples and the animal is weighed, Latti explained.

“We don’t use a tranquilizer, but the moose is relatively docile once it has been blindfolded,” he said.

Each moose is fitted with a GPS radio collar. The collars enable staff members to track moose locations and movements over time. They are also notified, via text or email, if a tagged moose dies.

In the spring and summer, adult cows are monitored to determine birth rates and the survival rates of calves. Biologists use the collars to collect detailed health information, including blood samples, parasite loads, body condition and winter tick loads. Winter tick infections can significantly impact the pregnant cows during the end of their pregnancy, causing extra stress on the body due to blood loss.

“This information is providing our researchers with an unprecedented, in-depth look at moose health,  including the impact of parasites on survival and reproduction,” Latti said.

The state also does aerial surveys to estimate the abundance of moose throughout Maine.

DIF&W contracts with Native Range Capture Services of Elko, Nevada, to capture and collar the moose. Money for the study comes from a federal grant (funded by the sale of hunting equipment) and the state’s dedicated moose fund.

The survival study is a collaborative effort involving DIF&W, the University of New Hampshire, New Hampshire Fish and Game, Vermont Fish and Game, and the University of Maine Animal Health Lab.