A study has found that the East is unlikely to be repopulated by lions that leave the densely populated Black Hills.

Faizan
9 Min Read
A study has found that the East is unlikely to be repopulated by lions that leave the densely populated Black Hills.

People have long thought of the large population of mountain lions in the Black Hills as a conveyor belt of animals moving eastward that will eventually lead to Puma concolor returning to old places they were pushed out of a long time ago.

The area is known as a lion-dispersal factory because animals with tracking bands that were put on in the isolated mountain range between two states have been seen walking in North Dakota, Minnesota, Colorado, Nebraska, and even further away.

In 2011, an uncollared cat that got lost and died in an SUV accident near Greenwich, Connecticut, had ties to the Black Hills genetically.

“Black Hills, Black Hills, Black Hills—that’s all people have talked about for years,” said Mark Elbroch, who used to study lions in Wyoming and now runs the puma program for Panthera, an international group that protects wild cats.

“Everyone said, ‘The Black Hills are the easternmost population,’ but that’s no longer the case. ‘And it’s the starting point for all of these crazy cats going into the Midwest or further,'”

But new study that Elbroch helped with calls into question the idea that the forestland spanning from Crook and Weston counties into South Dakota is an important part of the large carnivores’ ongoing recolonization of the United States.

“Our model shows that less than 1% of the cats that will be able to successfully set up territory, find a mate, and raise kittens will be from Wyoming,” Elbroch told WyoFile. “Wow, that was really surprising.” And the reason is that the risk of death is very high in the Dakotas east of Wyoming.

The latest peer-reviewed study by Elbroch, called “Limited cougar recolonization of eastern North America predicted by an individual-based model,” also doesn’t support the idea that lions will eventually be able to move into large areas of land that are now outside of their current range.

Even though places like Minnesota often have male mountain lions, slower-moving females must also make it for reoccupation to work. Then they have to find each other and have babies in a good place to live.

The study shows that’s easier said than done, which is a bad prediction, at least for people who support rewilding and have been watching the big cats successfully move east over the last couple of decades.

East is not going to breed out

Elbroch worked on the study with Tom Glass, who was a postdoctoral researcher at the University of Montana and also worked at Panthera under Hugh Robinson. The study was published in the journal Biological Conservation.

The main thing they found was that lions have pretty much run out of space, mostly because of dangerous things in the area that will keep them from getting there. They will only get back about 2% of the open range by the end of the century.

It was thought that mountain lions would never come back to the eastern United States. There was also only a 30% chance that they would be able to breed successfully in Oklahoma and Minnesota, which are on the edges of their current area.

Most likely, they would move back to Canada’s arctic forest. By 2070, there was a 95% chance that at least one litter would be born in Manitoba.

Road ecology was a big problem for both male and female lions when they tried to move and settle down. In models, highways were seen as death traps that stopped range extension.

It’s hard for them to get where they need to go because of roads, said Glass, who is now a postdoc researcher at the University of Alaska–Fairbanks. “To get to all of the places they’ve set up communities in the last 20 years, like the Black Hills and the Badlands, they haven’t had to cross that many busy roads.”

The study came to its conclusions by using a supercomputer to constantly simulate the attempts of different animals to spread out. Within the model, there was a “submodel” that looked at how cats try to cross roads and interstates on the land, which are changing the land more and more as cats move east.

Mountain lions’ ages, which affect how they behave around roads, were even taken into account in the road-crossing simulations: People their age don’t like crossing major roads, but kids are more likely to do it.

She said, “The interstates just get denser and denser and denser.” “I believe that’s what they run into as they shoot off in that direction [east].” Roads and people in fields protecting their jobs will be in their way.

The study found that mountain lion killing on the eastern edges of the current range was another big thing that made it less likely for the animals to move back.

Elbroch said, “This shouldn’t come as a surprise.” “Legal hunting changes the number of cats in the area.” It affects the number of kids who survive during spread, which is important to us.

Reports say that the South Dakota Game, Fish, and Parks Commission will think about a plan to cut the number of mountain lions in its part of the Black Hills from 200 to 300 to 150 to 250 at the beginning of October.

The Wyoming Game and Fish Department doesn’t keep track of how many mountain lions live in the state, but during shooting seasons, up to 51 cats can be killed in the three hunt zones that cover the Black Hills and the Bear Lodge Mountains next to them.

Lots and lots of lions

According to Elbroch and Glass’s study, Black Hills mountain lions that are moving away are not likely to come back to the east, but it’s not because there aren’t any cats there.

The only big area of Wyoming where mountain lions were wiped out during the settlement era was the Black Hills and Bear Lodge Mountain area.

But by the 1980s and 1990s, the sneaky native cats started to take over the area, which is usually full of deer, according to Dan Thompson, who is in charge of big mammals for Game and Fish.

Thompson said, “There are a lot of roads, so you can get around a lot of land.” “I’ve never been anywhere with so many lion tracks.”

Thompson actually looked into how lions moved around in the area in the early 2000s. A group of about twenty young cats were being watched, but they ran off in many different directions.

He said that the population in the Black Hills “definitely factored” into the return of mountain lions to the Badlands in North Dakota and Nebraska.

Those are now the most eastern people living in the US; it’s no longer the Black Hills. There are now breeding pairs in Nebraska all the way to the bluff country along the Niobrara River, which is more than halfway across the state.

Elbroch and Glass found that there is a small chance that cats will be born in Nebraska and safely move back to eastern North America. They found that people from farther north have the best chance of pulling it off.

Elbroch said, “The cats that are coming out of eastern Montana and eastern populations in Canada have the most success.” “They have habitat that is connected.” There aren’t many people living in this big, open land. The cats that go north are the ones that do the best.

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