Moving With The Moose - Northern Magazine

The 1,000-pound Michigan bull moose, standing 6 feet, 5 inches tall with 40-pound, paddle-like antlers, is the iconic symbol of the Upper Peninsula’s wildness. Despite their majestic status, Michigan’s moose have faced significant challenges over the past century. To understand the factors shaping their survival today, researchers are examining population trends and the hurdles moose encounter.

“Michigan’s moose are a vital part of the Upper Peninsula’s ecosystem and identity,” said Tyler Petroelje ‘10 BS, northern Michigan wildlife research specialist for the Michigan Department of Natural Resources. “Through this new study of factors limiting moose population growth, we’re working to uncover a clearer path for the future of moose in Michigan.”

DNR wildlife biologists have conducted aerial surveys to estimate the moose population in the western U.P since 1997. Every other year in January, survey planes fly low in a grid pattern over Marquette, Baraga and Iron counties as researchers record the number of moose spotted. Doing the survey in winter makes it easier for trained spotters to see moose against the leafless, snowy landscape, but it’s still impossible to count every moose. Instead, the numbers are adjusted using a statistical model to estimate the population. 

The 2023 U.P. DNR moose survey showed a population of 426 moose in the western part of the region. The 95% confidence interval estimates a range between 334 and 518 individuals. In addition to the regular aerial survey, researchers have just begun a new project later this winter to explore the reasons behind the slowed moose growth rate. The project is titled “Factors limiting moose population growth in the western Upper Peninsula.”

In this new effort, the DNR, Keweenaw Bay Indian Community and Northern Michigan University Biology Department (Lafferty, WECOS Lab) will work together to try to better understand the trends and challenges the Michigan moose herd faces. “As co-stewards of our shared land and natural resources, the Keweenaw Bay Indian Community welcomes the opportunity to work with the DNR and NMU to help answer important questions about the Michigan moose population,” said Erin Johnston ‘06 BS, wildlife and habitat manager for the KBIC Natural Resources Department in Baraga and NMU Biology alum.

Researchers plan to fit 60 moose with new tracking equipment over the next two years. During this first year of the study, this past February, the team fitted 20 moose—five calves, five bulls and 10 cows—with GPS collars to track their location. Tracking these movements will help researchers understand moose survival and causes of mortality, pregnancy rates and birthing events.

During the capture operation, spotter planes report moose locations to nearby helicopters and ground crews. Moose are sedated, and crews move in quickly to collect biological information and fit the moose with a tracking collar. The captures take place in mid-to-late February each year, depending on weather and other conditions, across the western moose range, in an approximately 500-square-mile block across the Michigamme Highlands.

“It was incredible,” said Petroelje. “In just 13 hours, the team successfully captured, collared and released the moose. Now, we have valuable data to refine our population model and frequent location updates that offer deeper insight into the life of a Michigan moose.” Just about a month later, the moose had already transmitted more than 10,500 GPS locations.

“There is a need to examine why moose population growth in the Upper Peninsula has been stagnant over the past decade,” said Diana Lafferty, associate professor in Biology at NMU. “As such, measuring vital rates like reproduction, survival, immigration, emigration, as well as identifying factors that may be limiting moose population growth, such as parasites, disease, predation, vehicle collisions and habitat alteration are essential for understanding and modeling population dynamics.”

Understanding the factors that limit the moose population is crucial for land and wildlife managers, as it provides insight into the broader ecological health of the Upper Peninsula. Furthermore, moose are culturally significant, as they are a symbol of Michigan’s wilderness and an important species for the traditions and practices of Indigenous communities in the region.

“Both the presence and absence of moose can affect forest growth, creating cascading effects throughout the habitat, impacting deer, birds, insects and plant life,” Petroelje said. “As a keystone species, moose have a disproportionate impact on their environment compared to most other species.”

By studying moose population trends and the challenges they face, wildlife managers can better understand the interconnectedness of species and ecosystems. This knowledge helps create better management strategies, ensuring that moose and the ecosystem at large thrive.