One of Minnesota's iconic animals has seen its population drop by almost half since 2005 as researchers try to identify causes.
Minnesota's moose took the first step toward endangered species status this week when the state proposed adding it to a new list of 591 plants, animals and insects that wildlife officials say need special attention to ensure their survival.
The state's moose population has dropped by almost half since 2005 -- to about 4,000 this year -- as a result of what researchers say may be disease, parasites, a warming climate or some combination of all three. Its new designation as "a species of special concern" would put an official stamp on the work already underway to save one of Minnesota's most iconic animals.
A spot on the endangered species list would make it illegal to hunt or kill a moose, but the animal's numbers are still too great to warrant that -- even though at the current rate of decline moose could be gone from Minnesota in 20 years. And until biologists figure out why adult moose are dying twice as fast as they should be, there is little state officials can do to protect it, experts say, including putting a moratorium on hunting.
"They are already concerned about the moose and doing a lot," said Ron Moen, a biologist and moose expert at the University of Minnesota, Duluth.
The new list of troubled and endangered species announced this week, the first update since 1996, also contained some good news. The Department of Natural Resources (DNR) proposed to end state designation for 15 plants and 14 animals that are doing well -- including wolves, bald eagles, snapping turtles and the trumpeter swan, which would be removed from the list because their numbers have recovered.
The little brown myotis bat and the big brown bat would be added to Minnesota's list as a species of concern because they face a potentially devastating disease called white nose syndrome that has decimated bats in other states and appears to be spreading. The Canada lynx, already on the federal list of threatened species, would make the state list as a species of special concern for the first time.
The boreal owl would become a species of concern, as would the northern goshawk, both birds of northern Minnesota's forests. The loggerhead shrike and horned grebe would move from threatened to endangered status. In all, the department proposed to add 67 animals and 114 plants to the list, bringing the current total to 591 species. About 17 are also classified as of concern, threatened or endangered on the federal list, said Rich Baker, endangered species coordinator for the DNR.
When researchers first detected the sudden decline in moose populations, they imprecisely dubbed it " tip-over disease" -- an apparently healthy adult moose dropping dead in the middle of summer for no clear reason. Since then, biologists have found a number of possible threats, including warmer summer temperatures that slow the animal's round-the-clock browsing, and susceptibility to a deer parasite that has exploded in Minnesota's northern forests.
"There is no question that there is an element of warmer temperatures," Moen said. "But we are not able to parse it out."
What confuses the picture even more is that moose seem to be moving into western North Dakota, not their normal region, and moving south from Maine to Massachusetts.
"So it is not just heat," Moen said.
This winter, biologists from the DNR and other research centers plan to track 150 radio-collared adult moose and calves in Minnesota and Ontario. They have set up teams across the state to find the carcasses immediately when the signal indicates a death -- so they can study a number of carcasses before they are eaten by scavengers or decompose.
That, Moen said, would give them enough information to determine if there is a clear pattern in the deaths.
An expanding list
The state's threatened species list was created in 1984 and last updated in 1996. At that time, the species removed included the wolverine, which was extirpated from the state, and many others that had recovered, including the marten, caribou, sandhill crane, osprey and dragon's mouth orchid.
Still, the number of species joining the list has risen far faster than the number removed, Baker said. That's because research into the status of thousands of Minnesota species has been underway for nearly 30 years. At first the list included well known "charismatic mega fauna" like eagles and wolves. Now, it also includes jumping spiders, moss and rare orchids that are more obscure, he said.
"They are all equally important," he said. "It takes all the pieces of the puzzle to make it fit together."
Public hearings to discuss the list will be held: Jan. 29, Ramada Hotel, Rochester; Jan. 30, New Ulm Community Center; Feb. 5, Bemidji Regional Event Center; Feb. 6, Gitchee Gumee Conference Center, Duluth; Feb. 7, Best Western Plus Kelly Inn, Plymouth.
Josephine Marcotty • 612-673-7394