The Associated Press reports Department of Natural Resources officials plan to collar 52 adult moose starting this week in an attempt to better understand what's killing off the herd.
The northeastern Minnesota moose will be outfitted with radio collars and stomach implants to track them. Researchers will be able to tell if their hearts stop beating or if the animals are still for six hours. They will then rush to the scene to investigate the cause.
Minnesota DNR spokesperson Michelle Carstensen said the agency wants to keep the study sample at about 100 animals, and replace 22 that died over the past year.
The DNR website explains that Minnesota's moose population has dropped 52 percent since 2010. The study to find the cause is entering its second year, and funding is being sought for a third.
DNR researchers also plan to collar 50 moose calves shortly after they're born this spring. Of the 49 calves collared last May, 36 have died, DNR research biologist Glenn DelGiudice said.
"We've got alarm bells ringing on both ends," Carstensen said. "We've got adults dying and a very high calf mortality rate. Neither of these things is good when it comes to wanting to have a stable moose population."
The DNR says hunting was not a major factor. Instead, scientists suspect changing habitat, a warmer climate, parasites and disease, some of which may be interrelated.