A two-year study to monitor cow moose with GPS collars in northwest North Dakota is winding down, and populations of the big animals continue to thrive in an area that historically wasn’t considered traditional moose country.
Someone forgot to tell the moose, who have found northwest North Dakota to their liking.
“It’s been pretty uneventful,” Jason Smith, big game biologist for the North Dakota Game and Fish Department in Jamestown, said of the moose research project. “We’re coming up on the end of the study, and what we basically found is they’re doing really well. We know that from the increasing population in the area. They have really good survival.”
As part of the study, Game and Fish in March 2014 contracted with a helicopter crew to capture and collar 20 cow moose along the Missouri River Bottoms outside Williston and 20 cow moose near the Sherwood and Kenmare, N.D., areas north and northwest of Minot to monitor movements and mortality.
Jim Maskey of the University of Mary in Bismarck has worked with Smith on the study and is the project’s coordinator. Maskey also coordinated a moose research project in central North Dakota about 10 years ago while he was a doctoral student at UND.
Before the study began, Smith said he and Maskey speculated the moose near Williston wintered along the Missouri River Bottoms and went elsewhere during other times of the year, especially when high water floods the area.
That hasn’t been the case. Maskey said the collared moose near Williston have an average annual home range of about 3½ square miles.
Even during floods, Smith said, the study moose along the Missouri River Bottoms move to adjacent higher ground and back to the river bottoms when the water recedes.
“Pretty uneventful for that part of it,” Smith said.
By comparison, moose in the Sherwood-Kenmare study block, where habitat is more fragmented, made longer migrations. Maskey said the prairie moose on average covered an area closer to 20 square miles.
“We saw a few moose that looked like they were seasonally migrating from winter to summer range,” he said of the prairie population. “It looked like they would leave their winter range in April, migrate someplace else, and two of the three that (made such a move) came back.”
The cow that didn’t come back drowned in November 2014 after falling through thin ice on the Mouse River after spending the summer near J. Clark Salyer National Wildlife Refuge northeast of Minot.
Maskey said he’s not sure what drives the moose to make their moves.
“It’s interesting that at least some of them have the potential to migrate,” he said. “My only guess is maybe it’s related to calving and could be something that’s learned from whoever their mother was.
“If anything, I would expect the late summer pattern is driven by where there’s sunflowers or corn, but even then, they’re eating mostly browse. I’m not sure what triggers them to move–sometimes, they just do weird things.”
Survival and production also are good in both study blocks. Maskey said cow moose during the first year of the study had a 95 percent pregnancy rate, and 36 percent had twins.
“About 80 percent of our moose recruited at least one calf,” Maskey said.
Annual survival approaches 95 percent, he said.
“That’s what you want to see for cow moose — especially in a population where there’s not much hunting harvest,” he said.
Moose numbers in the northwest part of the state have grown to the point where Game and Fish will be offering more licenses this coming fall. Smith said maintaining a population high enough to provide hunter opportunities yet staying within the bounds of landowner tolerance is a “real balancing act.”
Jeb Williams, wildlife chief for Game and Fish in Bismarck, said exact license numbers haven’t been announced, but he confirms there will be more moose — and elk — tags than last year.
The department is in the process of developing its moose and elk proclamations and setting license numbers for the 2016 hunting seasons.
“We’re going to be seeing some increased hunting opportunities,” Williams said. “They’ve been doing quite well on the prairies and rewriting the handbook for what moose like.”
Smith and other biologists say the general absence of parasites — specifically a snail that acts as a host for the brainworm parasite that’s fatal to moose — is one reason moose in western North Dakota are thriving while moose in more traditional areas such as the Pembina Hills and Turtle Mountains in northeast North Dakota and across northern Minnesota are struggling.
Also, hunters are the only real predators moose have in North Dakota, and their numbers are regulated by the number of once-in-a-lifetime licenses the department offers annually.
In Minnesota, by comparison, studies have shown wolves and bears both can have an impact on moose survival. Minnesota no longer offers a moose season.
“There’s very low mortality” in North Dakota, Smith said. “Knowing what the population is doing and that we have a lot of moose in that (northwest) part of the state, that’s not overly surprising, but we’ve been hunting moose up there for quite a few years so it’s good to have that biological background now to tie into it.”
Maskey said the researchers also set up data loggers both in willowed areas and more open country to see whether different habitat types provide better thermal shelter and how that influences moose locations at a given time.
There’s been speculation that climate change is a factor behind declining moose numbers in Minnesota.
“We’re not seeing the climate-related decline like they are in Minnesota,” Maskey said. “Here in North Dakota, people are seeing moose showing up almost down to the South Dakota border along the (Missouri) river.”
With the batteries on the collars reaching the end of their lifespan, the study now will make the transition from actively monitoring the moose to analyzing and working up the data. Maskey said a final report on the research project is due in June 2017.