Dr. Seth Moore and Tony Swader, Grand Portage Trust Land Administrator, are working to create better habitat for moose in Grand Portage.
Dr. Seth Moore has read the reports about deaths incurred when the Minnesota Department of Natural Resources (DNR) collared adult moose. About 20 percent of the moose died in 2013 during the initial capture/collar period. Not an acceptable number.
Still, Moore said, collaring is an important tool to help discover what is killing one of North America’s iconic animals. For the Grand Portage Band of Lake Superior Chippewa, the moose is vital to their sustenance and cultural way of life.
In 2006 the DNR estimated there were 8,500 moose in Northeastern Minnesota. Today their number is estimated to be 4,000. In Northwestern Minnesota the numbers are even bleaker. Twenty years ago the state said there were about 4,000 moose roaming the countryside. Today wildlife researchers estimate there are less than two dozen.
Is collaring to blame?
Why the decline? That’s the ten thousand dollar question and Moore said it could best be answered by continuing to let researchers track moose with GPS collars.
“We already know what happens when we do nothing,” Moore said. “We’ve done a lot of nothing and we’ve seen the results. Moose are continuing to die and we don’t know why.”
Minnesota Governor Mark Dayton recently suspended the state’s GPS collaring program because too many moose were dying from the capture/collar process. Many people greeted his declaration favorably, but Moore said if the public really knew what it lost when the program was suspended, people wouldn’t be so happy with the decision.
Grand Portage has been collaring moose since 2009. They have lost 2 percent of adults due to what is called “capture/collar mortality.” That’s well below accepted scientific standards for this practice.
And while Grand Portage lost almost no calves to abandonment after being collared in the first two years of study, in the DNR’s 2013 effort, one-fifth of the state’s collared calves were abandoned by their mothers and died. In 2014 all of the collars slipped off the calves or the calves died early in the study due to predation by bears and wolves.
The study ended almost before it began, but Moore stated, “It takes several years to get a reasonable understanding of the complex interactions that occur in nature.”
Tony Swader, Grand Portage Trust Land Administrator, is Moore’s boss. They are working together to create diverse habitat for moose on Grand Portage tribal lands, studying how different growths of plants and trees affect the animal’s success in foraging for food.
Swader said one of the biggest misperceptions is, “They think we are collaring every moose that’s out there. We’re not. Only 3 percent of the moose in Minnesota get collared. It’s not a lot.”
Moore agreed, adding, “As scientists we’re good at writing peer-reviewed articles about our work. However, scientists generally are not great at getting results to the public for whom we work. To help us figure out what is killing our moose, we need to collar them so we can track them, identify the issues, and study them in all kinds of conditions.”
DNR Moose Collaring
The Minnesota DNR uses helicopters to spot moose and when one is found it gets darted from the helicopter. Once down, blood samples are taken and a tooth is often pulled to check the age of the animal. A high-tech GPS collar is placed on the animal’s neck.
The collar transmits information about the animal’s movements to a researcher’s computer. Some are implanted with special transmitters (called mortality implant transmitters) that record internal body temperatures and transmit the information to the collar, which then sends it the researcher. This high tech equipment also records heart activity.
When an animal dies, a message is sent by text or email alerting a team that finds the moose within 24 hours. A certified pathologist performs a necropsy to determine what killed it.
Collaring in Grand Portage
Grand Portage also uses helicopters for adult moose capture, but uses much less tranquilizer to drop a moose. A $3,500 GPS collar, the same kind the state uses, is placed on the animal’s neck and blood samples are taken, but Moore said they spend far less time with the moose. Moore and his team note the physical condition of the darted animal and then go a safe distance away, watching to see if it rises safely and leaves.
“We don’t pull teeth. We don’t stick something in their stomach,” said Moore. “We think it is possible that these may add additional stress to moose.”
Moore added, “What we see sometimes is that the moose that die shortly after capture were going to die anyway whether we collared them or not. We know we have a health-compromised moose population and just by chance alone, some are in a state of dying from those health issues when we capture them.”
Once an animal is collared, Moore tracks its movements, noting the habitat in which it forages.
If it is killed or dies, a team from Grand Portage helps Moore bring it back to the Veterinary Diagnostic lab at the University of Minnesota where pathologists perform a necropsy. Moore’s findings are very different than the findings of the state’s wildlife biologists.
What is killing Minnesota’s moose?
Theories abound, and everything from global warming to disease, brain worm, flukes, predators, and lack of good habitat is suspected, but no one knows for sure what is killing Minnesota’s largest wild animal.
While some researchers are finding that predation by wolves and bear are causing the biggest decline in adult moose numbers, Moore is finding something entirely different. Over the past six years he has collared and tracked 92 moose, and of those adults that have perished, only a small number can be attributed to predation, he said.
“In adult collared animals I am finding that 80 percent of them die from health related issues or parasites. Nearly 40 percent show neurological symptoms caused by brain worms, which is a natural parasite of deer.
“Maybe if we managed our deer population better more moose would live. We could do that by increased deer harvest by hunters or altering the habitat so there isn’t as much interaction between deer and moose, which would also reduce brainworm infection.
“But the only way we will know that is if we collar. Using collared moose, we can measure whether moose mortality rates from brain worm decline with the implementation of such management strategies. Perhaps managing for low deer population levels in core moose range can help restore the moose population,” he said.
Winter ticks are also killing moose, but their effects on cows that live through the winter also can’t be forgotten. “Those cows come into the spring weak and malnourished and their calves can be sickly,” Moore said.
It is these animals, suspects Moore, which wolves prey on.
“I don’t see much predation by wolves. Six percent of the adults I have studied can be attributed to wolf kills. Wolves kill moose that are dying. At least in Grand Portage I think they do a lot of scavenging, not preying on healthy moose,” he said.
Calf mortality high— with or without collars
Moore has been collaring calves since 2013 and found that whether a calf is collared or not it has less than a 30 percent chance of living to complete its first year.
Like the Minnesota DNR studies, Moore found that bears or wolves take 70-75 percent of calves within the first few weeks of their lives and further, up to 15 percent have other health issues such as stillbirth or lethal infections. This means that only 10 percent of moose calves are making it through their first year of life.
“These results suggest that calf survival and recruitment may be improved by controlling bear or wolf numbers through hunting seasons,” said Moore. “As a natural resources management action, in Grand Portage we have initiated a spring bear hunt to enable higher bear harvest and reduce predator density on the landscape.
“By continuing to collar moose calves and monitoring survival, we can measure whether calf mortality rates decline with increased bear harvest. Perhaps managing for lower predator population levels in a core moose range can help restore the moose population,” said Moore.
Maternal conditions monitored
The Grand Portage moose project is the first Minnesota-based study to have collected blood samples from neonate calves, and while it’s still early, the study is intriguing.
“The goal of this study is to determine how the maternal health of moose may be related to moose calf survival,” said Moore. “Preliminary findings suggest that in years when maternal health in moose is poor, calf immune system health may also be compromised early in life.”
Like human infants, the immune defense of a neonatal calf is derived in large part from the passive transfer of maternal antibodies through milk in the first day of life. “Since this work began in 2013, we have seen trends in neonate antibody levels among sampled calves that may correlate with winter body condition and annual mortality rates of adult collared moose.
“These early findings reveal important links between environmental conditions, adult health, and calf survival and call for continuation of this type of research to understand the impact of health in calf recruitment,” Moore said, adding that this can only be accomplished if cows and calves can be tracked through GPS collars.
What’s ahead for researchers?
James Forester, an assistant professor, Department of Fisheries, Wildlife, and Conservation Biology at the University of Minnesota, is sending a PhD student this fall to work with Moore on the moose study. Moore is excited about getting a young scientist involved with this project.
Because moose only use 35 percent of available land in Grand Portage, Moore and Swader will work to improve several habitats using different plants and trees to see what works to create the best forage for these herbivores.
“We suspect that much of the moose range in northeastern Minnesota is lacking in quality habitat for moose similar to what we have observed in Grand Portage. Our future research focuses on identifying the most effective habitat improvements that can be made to benefit moose so that we can apply habitat improvements over a large scale,” Moore said.
And Moore said, “We are asking the governor to reevaluate his decision to halt moose collaring research and carefully consider the implications of the loss of this necessary government-led and sponsored research to the Minnesota moose population.
“We would like to see the resumption of DNRconducted and permitted research and finding so that informed decisions are made to benefit moose and that the effectiveness of these decisions can be fully evaluated,” said Moore, concluding, “We think that a broad moose research community provides the greatest long-term benefit of the species.”
About moose
At anywhere from 950 to 1,250 pounds, an adult moose is the largest wild animal in the state of Minnesota. A male’s antlers can spread 5 feet across and weigh 40 pounds. It stands 6–6 ½-feet tall and its body is 9-10-feet long. Due to their long legs they move well through deep snow. They are excellent swimmers and can dive to the bottom of a lake or shallow pond and tear out vegetation to eat. Dark brown to black in color, it doesn’t take long for them to disappear into a boreal canopy.
Moose can run 35 miles per hour and swim 10 miles or more without stopping. They can store 100 pounds of food in their stomachs.
A cow usually gives birth to one calf that weighs between 25-35 pounds. Occasionally a cow gives birth to two calves and as we’ve seen from a recent frontpage picture in the Cook County News-Herald by photographer by David Johnson, a cow can give birth to three calves. Calves stay with their mother for 12 to 18 months.
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