Moose are animals made for cold weather, so when the temperatures rise in their environment, it can lead to exhaustion-related death. Now, scientists are trying to discover if that’s been the cause of a recent upsurge in deaths, as the population has shrunk dramatically–from 8,000 to 3,000 in Minnesota alone.

As wildlife officials investigate the cause, they’ve suspended moose hunting in Minnesota, and other states–like Montana–have seen a dramatic drop in hunting permits because the animals are getting too hard to find.

“Something’s changed,” said Nicholas DeCesare, a biologist with the Montana Department of Fish, Wildlife and Parks. “There’s fewer moose out there, and hunters are working harder to find them.”

There are several factors that might be contributing to the decline in population, and weather is just one of them. Ticks, for instance, have reportedly been a big concern and, not surprisingly, the longer periods of warm weather have also affected the pests. They tend to be out in full force until it gets very cold, and a moose is prime feeding ground. A large tick infestation means a moose may become anemic, and they also scratch until their hair falls out, which can lead to hypothermia when the weather finally does cool off.

Minnesota is one state trying to track the source of the die-off; by fitting several of the animals with tracking collars and tiny monitors that keep track of the heart rate, they can see the exact moment a moose dies and get to it quickly no matter where it is in the wild. Time is of the essence where a moose necropsy is concerned, because they decompose quickly.

“If the heart stops beating, it sends a text message to our phone that says, ‘I’m dead at x and y coordinates,’ ” said Dr. Butler, who is leading the project.

It will take a while to get to the root of the deaths, but scientists hope that the next few months will bring answers that could help save the population.