A new scientific study adds evidence to claims that landowners who don’t allow public access contribute to elk overpopulation.

On Thursday, at a Wildlife Society meeting in Missoula, Montana Fish, Wildlife & Parks biologist Scott Thompson presented research out of the Missouri River Breaks area showing that elk, not surprisingly, tended to harbor on properties that exclude public hunters.

Thompson and three other FWP biologists compared the loitering behavior of two elk herds by tracking the movements of four dozen collared cow elk during the hunting season over two years. They chose to compare a herd in Hunting District 621 in the Breaks, an accessible area that is 87 percent public land, to a herd in the slightly less-accessible Larb Hills, HD 622 and part of 631, which is 69 percent public land.

Elk populations have been over-objective in the Missouri River Breaks area for at least the past decade, Thompson said. For HD 620, 621 and 622 combined, the population objective is 1,400 to 1,650, but biologists estimate the three districts hold more than 2,400 elk, according to the 2015 counts.

In spite of the large numbers of elk, Thompson said the hunting success rate in the area has declined from 60 percent in 2000 to about 10 percent last year. A limited number of elk licenses are offered each year - 2,000 archery and 1,200 rifle licenses – although FWP has upped the number of antlerless licenses as the population has increased. In 2016, 80 either-sex tags will be available.

For the study, biologists classified parcels within each area as accessible, not accessible and restricted. In HD 621, the herd’s fall range is 97 percent accessible and 2 percent is inaccessible, while in HD 622, 79 percent is accessible and 11 percent is inaccessible.

They also looked at other aspects that might influence elk preference, such as terrain roughness and nearness of roads and cover. However, while elk normally avoid roads, Thompson said so many roads run through both areas that there aren’t many roadless areas for elk to choose.

The study found that elk moved differently in the archery season than they did in the rifle season. Elk sought out inaccessible areas more during archery season especially in HD 621, although Thompson wasn’t sure why.

“We have a large participation in archery hunting in the area. Whether archers use the landscape differently than rifle hunters could probably be another study but they are affecting the way those elk use the landscape,” Thompson said.

In HD 621, 30 percent of the collared elk stayed in inaccessible areas during the archery season. While that doesn’t seem like a large amount, remember that only 2 percent of the herd’s range is inaccessible. So one-third of the elk chose to stay in a tiny area, which turns out to be the Slippery Ann Wildlife Viewing Area. However, during rifle season, only 9 percent of elk harbored in the inaccessible area.

In HD 622, slightly more elk - 40 percent - sought out inaccessible areas during archery season, dropping to 30 percent in the rifle season. But again, about one-third of the elk are staying in an area that is just 11 percent of the district.

“It’s no surprise that we found that relatively small geographic areas managed for no access have this disproportionate effect on elk distribution,” Thompson said. “So that really limits our effectiveness to use antlerless harvest.”

Shoulder seasons have been approved for cow elk on private property in HD 620-622, but based upon this study, few elk will remain long on private land to be hunted.