Gov. Mark Dayton on Tuesday put an end to Minnesota's ambitious moose research project out of concern that human interference is harming the very animals it's trying to help.

In the past two years about a fourth of 75 newborn moose were abandoned by their mothers after researchers attached sophisticated GPS collars to them. And this year five out of 32 adult moose died after being collared.

The $1.7 million research project was launched three years ago, part of a determined effort to find out why Minnesota's moose are declining at such a perilous rate. Their numbers have dropped to 3,450 animals in the northeast corner of the state, down 60 percent in less than a decade.

"I respect that [state] researchers are trying to understand why our moose population is declining," Dayton said. "However, their methods of collaring are causing too many of the moose deaths they seek to prevent. I will not authorize those collaring practices to continue in Minnesota."

The deaths were not enough to hurt the moose population as a whole, said other experts. Moose give birth once a year, so there are more than a thousand calves born annually. But the high rates of post-collaring abandonments and deaths for one of Minnesota's most beloved animals posed a serious ethical dilemma for scientists and elected officials.

Tom Landwehr, commissioner of the Department of Natural Resources, compared Dayton's decision to one made in 2013 to end the hunting season for bulls. As it turned out, the few that were shot by hunters did not affect the overall population.

"But the only thing we can control is human-induced death," Landwehr said.

Just a few weeks ago Dayton said that this would be the last year for the moose calf study because of the high rate of abandonment. But, Landwehr said, he decided to end both ends of the research project now after hearing about the unusually high rate of adult moose deaths that occurred this year. The order applies to all researchers in the state except those on tribal and federal lands.

The Legislative-Citizen Commission on Minnesota Resources (LCCMR), which partly funds the project with lottery money, also heard complaints from a few members of the public.

Monica Bultena was one. She helped organize an online petition to persuade the DNR to stop the moose calf portion of the project; her efforts drew about 1,600 people in support. They also met with the LCCMR.

"They needed to stop that portion of it," she said. "You don't interfere with a newborn wild animal. It's never going to have good results."

Dayton's executive order puts an end to any new information about why 70 percent of calves die before they reach their first winter. Their collars are designed to drop off in less than a year.

From the 75 that were successfully collared, they found that the vast majority are killed by wolves and bears.

But there still are 99 adult moose with collars. Their collars, with a two-year battery life, will continue to send out sophisticated real-time data about the animals' location, activity and body temperature and a death signal that allows scientists to locate the carcass within 24 hours for an immediate autopsy.

"Being able to get there in 24 hours is so illuminating," said Michelle Carstensen, who is heading the adult moose project for the DNR.

Of the 36 adult moose deaths, about half were attributed to wolves, a rate that researchers found surprising. The predators either killed the moose outright or caused injuries that eventually led to their death, Carstensen said. But most of the moose that were killed by wolves also had some other problem that weakened them — an infection or parasite, she said.

The other half have died directly from infections and parasites like brain worm, which come from deer, or winter ticks, which sap moose of blood during the winter.

Sixty-one moose also carry temperature reading devices in their stomachs, and eight of the animals that have died had an unusually high body temperature, she said. While not conclusive, it raises the possibility that the state's increasingly warmer summers may be affecting the moose as well.

But the research does not explain why so many calves were abandoned, or why this year so many adults died.

Last year, the DNR launched a rescue project to bring abandoned calves to the Minnesota Zoo, saving six of them. Researchers also drastically shortened their handling time, which also seemed to reduce the rate of abandonment.

But Carstensen said she could not explain why adult moose were also so traumatized by the collaring. Researchers in Minnesota and elsewhere have been collaring adult moose for years. Capture trauma occurs occasionally, but rarely at the rates seen this year in Minnesota.

The moose don't die — but they can't get up. They are called "downers," just like cattle. The scientists tried injecting them with steroids and other medications, but in the end one died on its own and four others had to be euthanized in the woods.

They had planned to collar 37, but Carstensen called a halt at 26 after the fifth death.

"I'm as perplexed as anyone," she said.

Josephine Marcotty • 612-673-7394