Research team tracks moose at Isle Royale National Park
The University of Minnesota College of Veterinary Medicine and Grand Portage Band of Lake Superior Chippewa partner to compare mainland and island moose populations
ISLE ROYALE NATIONAL PARK, MICHIGAN --- Following the reintroduction of several collared wolves from the Grand Portage Indian Reservation in Northeastern Minnesota to Isle Royale National Park last fall, a team of researchers have now collared moose at the park for the first time since 1984. The unique collaboration between the University of Minnesota College of Veterinary Medicine (CVM), Grand Portage Band of Lake Superior Chippewa, National Park Service, and Michigan Technological University aims to help the National Park Service assess the impacts of predator restoration to the ecosystem at the park.
This effort marks the beginning of a novel effort to compare the predator-prey dynamics and health of the population of moose on Isle Royale National Park to a neighboring population of collared moose on the mainland on the Grand Portage Indian Reservation. It also represents an opportunity to evaluate the impact of restoring predation to the ecosystem.
Between February 13-17, 2019, a helicopter anesthesia darting team, a wildlife veterinarian, and wildlife research biologists fitted 20 cow moose with GPS collars on the west and east sides of the island. The team collected biological samples from the anesthetized moose, assessing individual moose health, and fitting them each with a collar. Afterward, each moose was administered a reversal drug—they all awoke and walked away in under two minutes. Since then, movement activity has been continuously monitored by GPS.
The team plans to conduct various studies with the data they have collected. They are looking to understand what impacts health of moose populations on both the mainland and Isle Royale, how predator dynamics play a role in moose populations, how differing forest management affects the ecosystem, and how climate may play a role in ecosystem health.
Isle Royale hosts a simple ecosystem with one predator species, wolves, and one primary prey species, moose. This makes it an ideal system for comparative research with mainland populations of moose, such as those found on the Grand Portage Indian Reservation, which hosts a more complex ecosystem with multiple predators and multiple prey species. Mainland populations of moose are in decline due to predation from bears and wolves on moose calves in early spring, as well as compounded effects of climate change, which includes parasitism from brainworm (transmitted by the invasion of whitetail deer into moose range), and high winter tick loads due to early snow melt.
By contrast, the moose population on Isle Royale has increased rapidly in recent years. Although moose in Isle Royale also suffer from high winter tick loads, the Isle Royale population of moose does not have deer to transmit brainworm. Another crucial difference is that wolf numbers are high on the mainland (due to high deer densities), whereas the island only has a few remaining wolves predating on the moose population.
Over the last two decades, the island’s wolf population suffered from inbreeding depression that drove the population to the brink of extinction. That circumstance is an indirect consequence of climate change, which led to fewer ice bridges forming between island and mainland, preventing wolves from moving to and from the island. The impact of the growing moose population on forest vegetation is increasingly apparent and experts are concerned that such high levels of browsing damage are impacting forest regeneration and may eventually lead to nutritional stress for moose.
The contradictory population trajectories between Isle Royale’s wolves and moose and those on the mainland create an ideal opportunity to better understand by comparison what ecological factors are impacting each population. “This is a unique opportunity to explore the health of a species through the comparison of two populations under a different set of pressures alongside experts from different scientific disciplines and with their own distinctive skillsets,” says Tiffany Wolf, DVM, PhD, assistant professor in the Veterinary Population Medicine Department at the CVM. Wolf is one of many collaborators on the project. “That kind of collaboration brings research to the next level and affords the opportunity to attain new insights into population health that might otherwise not be realized.”
“This is a unique opportunity to explore the health of a species through the comparison of two populations under a different set of pressures alongside experts from different scientific disciplines and with their own distinctive skillsets,” Tiffany Wolf, DVM, PhD
Decades in the making
The Grand Portage Band of Chippewa has more than 250 years of stewardship of Isle Royale. UMN has conducted research on wolf-moose interaction on the island for 45 years. UMN and Grand Portage have been collaborating to study moose health and habitat use since 2009. The decade-long partnership has since expanded to explore other aspects of health related to species important to the Grand Portage Band of Chippewa.
“The Grand Portage Band of Chippewa were the historical occupants of Isle Royale and used the island for subsistence purposes.” says Seth Moore, PhD, director of biology and environment at the Grand Portage Band of Lake Superior Chippewa. “We hope to learn how to better manage moose populations from this research.”
The team of researchers are led by Tiffany Wolf, DVM, PhD, assistant professor in the Veterinary Population Medicine Department at the University of Minnesota College of Veterinary Medicine; Seth Moore, PhD, director of biology and environment at the Grand Portage Band of Lake Superior Chippewa; Rolf O. Peterson, PhD, research professor, Sarah R. Hoy, PhD, research assistant professor, and John A. Vucetich, PhD, professor, of the School of Forest Resources and Environmental Science at Michigan Technological University; and Mark Romanski, MS, chief of natural resources for Isle Royale National Park. This team collectively has decades of experience concerning moose and wolf research, as well as the ecosystems in which the project occurs.
Funding for this project came from National Park Service, National Science Foundation, Michigan Technological University, Great Lakes Restoration Initiative and Grand Portage tribal government support, and many generous private donations to the Isle Royale wolf-moose project.
Tiffany Wolf, PhD, assistant professor, Veterinary Population Medicine, University of Minnesota College of Veterinary Medicine, [email protected], 612-625-0492
Seth Moore, PhD, Director of Biology and Environment, Grand Portage Band of Lake Superior Chippewa, [email protected], 218-370-9310