A study launched last winter to help determine why the state's moose population is declining so rapidly is finding a higher than expected mortality rate among calves.
Previous studies have shown that about half of all moose calves die within their first year of life, but young moose being studied in northeast Minnesota are dying at a faster pace.
The Duluth News Tribune reports 71 percent of calves in the study have died during their first four months of life and the remaining calves still have a winter to survive ahead of them.
“The very rough estimate in Minnesota is that we have been down to about 28 percent survival in recent years. But we still have seven months to go and we’re already there. That’s not good,” Glen DelGiudice, lead moose researcher for the Minnesota Department of Natural Resources, told the newspaper.
The moose population in northeast Minnesota, the primary area of study, was cut in half over the past three years. Without intervention, researchers say the population could disappear entirely by 2020.
The Minnesota Department of Natural Resources captured and collared 49 moose calves and more than 100 adult moose for the study. Implant transmitters notify researchers via text message or email when a moose dies, along with coordinates for finding the carcass and a log of vital statistics.
For moose calves, the major cause of death is predators. The Duluth News Tribune says 16 calves were killed by wolves and four were taken by bears.
Right after capture by the DNR, 11 died. Most were abandoned by their mothers.
DelGiudice doesn't think predators are what caused the steep decline in the moose population, but they're having an impact.
“When we had 9,000 moose and the same number of wolves, the number they took was far less significant and likely not impacting the population,” DelGiudice said. “But with fewer than 3,000 moose now, and roughly the same number of wolves, that predator-to-prey ratio has changed."
Researchers will be watching closely to see how the remaining 10 calves fare this winter.
As for the adult moose, 19 have died, which is also more than expected.