A tourist hangs out a car window to photograph a bison in Yellowstone National Park.

Last year Yellowstone National Park tourists seemed to hit new heights for weird behavior. In a couple of instances, it was even deadly.

One tourist loaded a baby bison in the back of his vehicle and drove it to the nearby ranger station because he thought it was cold and abandoned; a woman was filmed petting a full-grown bison on the head; a roving band of filmmakers captured their illegal romp on a delicate thermal feature on camera and posted it online; and one man’s exploration for a place to soak in hot water ended with him falling into a steaming, acidic pool and being boiled alive.

“You kind of hit your head and wonder, ‘What was he thinking?’” said Norma Nickerson, a research professor at the University of Montana and director of the Institute for Tourism and Recreation Research.

Why is such foolishness on the rise?

“There are a few different theories going around,” Nickerson said.

One is our society’s attraction to the point of distraction with social media – platforms like Facebook, Twitter and SnapChat. Posting a selfie with a bison may encourage others to take a similar risk. Or feedback glorifying a person’s behavior may embolden them to take ever greater risks.

Bison jam

Signs warn of bison on the road as a line of cars slowly crawls along the Grand Loop Road in Yellowstone's Hayden Valley.

People taking selfies also will make the mistake of turning their back on wildlife so they can both be in the photo, said Linda Veress, Yellowstone spokesperson. The park requires people to stay 25 yards from most mammals, but in 2015 two people were gored by bison after they walked within 3 to 6 feet, she said.

Another possibility is that because more people than ever live in cities, far removed from animals in general and wildlife in particular, they don’t know how to act.

“The bison do seem docile, it’s hard to believe they can run 30 mph,” Nickerson said. “They look pretty friendly.”

More tourists than ever are taking photos with cellphones or iPads. Without a zoom lens they often get closer to their subject to take a good shot, putting them at risk of falling off a cliff or being gored by a bull elk.

As Nickerson noted, it only takes one person to wander closer to a black bear to prompt others to follow, what she called “group think.” Veress said that at times so many tourists will surround an animal that it feels threatened and acts defensively.

“You can’t have a ranger at every bear and bison crossing,” she said. “So you’re on your own.”

Surveys of Mandarin speaking tourists in West Yellowstone revealed that some of them thought that if the animals, geysers or fumaroles were dangerous, the government would fence them off because that’s what they do in China.

“In their culture they feel it’s not dangerous,” Nickerson said.

Prismatic walk

Three Canadian men are facing charges for walking on geothermal features in Yellowstone National Park and posting the photos on Facebook.

Another reason could be as simple as statistics: More people are visiting the park so it is more likely that there will be people who are ignorant about proper behavior around free-roaming wildlife and hot pools.

Last year was another record year for visitation, with more than 4.25 million people mixing with record-high populations of bison and more distracted drivers.

Those distracted drivers create a hazard by stopping in the middle of the road, jumping out of their cars or backing up traffic that can lead to other drivers dangerously passing.

“That’s something we see just about every day,” Veress said.

Last year a woman was so excited to see a bald eagle perched in a nearby tree that she pulled over, stepped out in front of an oncoming vehicle, was struck and died. Veress said that incident points to a lack of situational awareness in a different environment.

“Another thing we see quite often is people disregarding signs,” Veress said, everything from orders to stay on boardwalks to not walk on thermal features.

Some parks with limited access, such as Zion in Utah and Denali in Alaska – have already restricted visitation by requiring entry by bus only. Having tourists crowded into one confined space allows tour guides or interpretive rangers to educate travelers about proper behavior. But Nickerson doesn’t see that happening in such a large place as Yellowstone or Glacier national parks, with their multiple entry points, any time soon.

“I’m pretty sure parks don’t want to go that way because parks are for the people,” Nickerson said.

Yet the National Park Service is also charged with protecting the natural resources under its care. What is the tipping point?

“You are always going to have some people who go around the rules,” Nickerson said, but social media seems to have embolden more people to take those risks, she added.

“It’s very powerful and immediate.”