The North Shore’s penchant for dishing out harsh winter weather hasn’t deterred Minnesota Department of Natural Resources (DNR) wildlife researchers from fitting high-tech GPS collars on 31 moose to help answer why Minnesota’s moose population continues to decline.
“We started the project last week near Grand Marais during a four-day stretch of extreme cold,” said Lou Cornicelli, DNR wildlife research manager. “Flight safety guidelines dictate no work can be performed below 20 degrees below zero. So despite the fact the helicopter was grounded for most of the first three days, we successfully collared and now are tracking nearly a third of the moose we plan to study.”
Capture and ground support crews wrestled with daytime wind chills that plummeted to as cold as 54 below zero on Monday, Jan. 21, and air temperatures that didn’t rise above zero until Thursday, Jan. 24.
“By this date when temperatures warmed, the helicopter capture crew was fully trained, allowing them to collar at least five to six moose a day,” said Erika Butler, DNR wildlife veterinarian.
Capturing and collaring adult moose is the first phase of a multiple-year project to attempt to determine why moose are dying at unusually high rates in northeastern Minnesota. The DNR intends to put collars on 100 adult moose in the Grand Marias, Ely and Two Harbors areas in the weeks ahead as part of the most sophisticated moose research project ever conducted.
Even among veteran researchers, the massive and majestic animals continue to be a source of awe. The possibility of their disappearance from Minnesota remains troubling.
“When you watch a collared moose disappear back into the brush, you hope the data will help unravel the mortality mystery that is puzzling wildlife managers,” Butler said. “The technology we helped develop for this project will be of use to other researchers.”
The DNR study is primarily about better understanding the causes of moose mortality. Annual population estimates show that Minnesota’s northeastern moose population has declined significantly since 2008. About 20 percent of adult moose die annually, although the exact causes of that mortality are not well understood. Previous research has demonstrated that hunting and predation by wolves are not the primary causes of adult deaths, and multiple signs indicate the causes are likely health- and stress-related factors.
Butler said that pending good weather and no serious operational problems, the DNR will be tracking 75 cow and 25 bull moose by mid-February.
“Signals sent from the 31 moose we have collared as of Monday afternoon are already providing us with their precise location,” she said. “Sensors are recording the air temperature around them and, in some cases, their internal body temperature and whether their heart is beating. If a moose dies, we will receive a text message so that researchers stationed in the field can get there within 24 hours to allow for a necropsy and other tests to better understand the cause of death.”
The body conditions of moose collared so far have varied, but many have been on the thin side, Butler said. Bulls tend to fare worse than cows in winter because bulls have less body fat after the fall breeding season depletes their nutritional reserves. These reserves are difficult to build following the breeding season with the sparse browse available in winter.
One bull moose was euthanized shortly after being collared and released. The animal was in poor physical condition. Although the necropsy has not been finalized, initial findings indicate that the young bull was in too poor of shape to recover from being immobilized. Butler said it’s not unusual to encounter unhealthy animals as part of a large research study, and that’s especially true for studies focusing on a species in decline.
DNR’s research project is funded by the Minnesota Environment and Natural Resources Trust Fund. This is a permanent fund constitutionally established by Minnesotans to assist in the protection, conservation, preservation and enhancement of the state’s air, water, land, fish, wildlife and other natural resources. This $1.2 million project was recommended for funding by the Legislative-Citizen Commission on Minnesota Resources. It will build on research that is ongoing or planned by other agencies and universities.
A second phase of the project will examine moose calf mortality. After calving in spring, the locations of cows collared this winter will be used so their calves can be located, captured and fitted with collars that will provide data similar to that being collected from adults. Data from calves will provide much-needed information about calf survival and causes of mortality.
Cornicelli said it’s premature to speculate on how the research information may be used. America’s successful wildlife management system, he said, is based on research that provides previously unknown insights that can then be applied to management.
“In this stage, we are collecting data,” he said. “As that data is accumulated, we will evaluate it. Only then will we know what, if anything, can be done to stop or reverse the moose population decline.”
Partners in the project include the University of Minnesota-Duluth, Fond du Lac Band of Lake Superior Chippewa, 1854 Treaty Authority (Bois Forte and Grand Portage Bands); the University of Tennessee, the Smithsonian, and the University of Minnesota.
Research project updates and additional information about moose management and research are available on the DNR website at www.mndnr.gov/moose.
Image courtesy Minnesota DNR