Dr. Seth Moore – Grand Portage Wildlife Biologist

Wolves could play key role in preventing parasite from killing Minnesota moose

A study from the University of Minnesota College of Veterinary Medicine and the Grand Portage Band of Lake Superior Chippewa published this month in the journal Science Advances offers a new theory on the role of wolves in disease transmission among prey, including moose.

The research shows that nearly a quarter of collared moose that died in northeastern Minnesota over the past 15 years were infected with a brain worm parasite transmitted by white-tailed deer that is one of the biggest threats to adult moose mortality in Minnesota.

The study was conducted in and around the Grand Portage Band of Lake Superior Chippewa Reservation and near the Lake Superior shoreline, where researchers have for years been studying moose in an effort to understand and reverse a long-term moose population decline.

“Understanding the effects of managing predators and prey on the landscape is an area of research that needs considerable attention in an experimental fashion,” said Seth Moore, director of biology and environment for the Grand Portage Band and co-principal investigator of the project. “The results of the study really illustrate that predator-prey dynamics may impact wildlife disease and overall ecosystem health. Our applied research to restore moose in Minnesota will incorporate this new and important area of study for ecologists and epidemiologists by using approaches that combine predator-prey dynamics with the interactions of disease.”

For this study, researchers captured and tracked 94 adult moose, 89 deer and 47 adult wolves during the 2007–2019 study period.

The study found that most deer and moose performed seasonal migration, with different habitat selections by the two species. The research also showed that deer and moose overlap increased during the spring migration and summer seasons – a time of greatest brainworm transmission risk. Perhaps most unique among the findings was the fact that wolf pressure was linked to greater segregation of deer and moose across habitats – and reduced brainworm transmission risk.

“We often think of wolves as bad news for moose because they kill a lot of calves,” said principal investigator Tiffany Wolf, an assistant professor in the UM Department of Veterinary Population Medicine who was involved with the study. “But this suggests that wolves may provide a protective benefit to adult moose from a parasite-transmission perspective. Because brainworm is such an important cause of adult moose mortality in Minnesota, we can now see that the impact of wolves on moose is a bit more nuanced.”

The findings give state and tribal managers new information to consider in drafting and implementing herd and wolf management plans in Minnesota and beyond. Maintaining healthy moose populations is a central goal of tribal managers, as moose are an important subsistence species for the Grand Portage Band and important to cultural preservation.

WTIP’s Joe Friedrichs spoke with UM Professor Tiffany Wolf about the research.

Friedrichs also spoke with Seth Moore, the director of biology and environment for the Grand Portage Band of Lake Superior Chippewa about the research and what it means for management of various species. The audio to both interviews is shared below.