Yellowstone National Park rangers have contended with their share of notorious human misbehavior over the years, whether it’s guests vandalizing the fragile geothermal wonders, poachers killing trophy elk, illegal inner-tubers being swept away in the raging Yellowstone River, or overzealous animal lovers harassing wildlife, sometimes with deadly consequences.

As Rick Wallen says, few things tourists do are surprising, yet within the last week Yellowstone’s senior bison scientist learned of an incident that left even him speechless.

A pair of international travelers making their way through the wildlife-rich Lamar Valley in early May was arrested and ticketed after they allegedly caught a wild newborn bison calf from the roadside, loaded the animal into their vehicle and drove it to a ranger station. The motivation for their brazen action: They believed they were being Good Samaritans, rescuing the bison because it appeared to be abandoned and shivering in the cold.

Tragically, the calf was euthanized May 10 after park biologists tried numerous times to reunite the snatched buffalo with its herd but the youngster was rejected, some speculate, precisely because of its handling by people.

So far in 2016, a spate of similar outlandish tourist incidents with animals has put park officials on edge. One video posted on Facebook showed a woman petting a clearly agitated bison along the boardwalks near Old Faithful Geyser. At another venue, a group of visitors tried to pose for selfies with bison only inches away from the startled one-ton beasts.

As America’s iconic nature preserve braces for record numbers of visitors, Yellowstone took the unusual step this week of issuing a press release that encourages the masses to keep their distance and mind their manners.

“We see the need for a call to action. We’re already having problems and the busy summer season hasn’t even begun,” park spokeswoman Morgan Warthin says. “Visitors need to know the safety regulations and respect the wildlife they are coming to see. The well-being of these animals depends on visitors exercising good judgement.”

Last year five visitors were seriously injured when they approached bison. In fact, more people have been harmed by bison during the last decade than grizzly bears. (Read more about problems in Yellowstone.)

Stupid Human Tricks

As Warthin’s boss, Yellowstone Superintendent Dan Wenk says the biggest challenge isn’t managing bruins, bison, and elk, but keeping uninformed people from bumbling into trouble.

“The last couple of years there’ve been a lot more people, especially people associated with bus tour groups, invading the spaces of wildlife,” Wallen says. “I attribute some of the aggressive behavior to the impact of social media and the selfie craze where visitors try to get pictures of themselves standing as close to big animals as possible. They don’t realize the serious risks they’re taking. They’re setting themselves up to be candidates for a Darwin Award.”

Darwin Awards, offered as feats of dubious distinction, are given in honor of individuals who do stupid or ill-advised things that remove themselves from the human gene pool. Many suffer death caused by misadventure or bad judgment. (See the park's "bear bathtub.")

In 2015, Yellowstone notched more than four million visits for the first time in the park’s 144-year history, up 17 percent from the year before. An even larger increase occurred in tour bus visitation, which has doubled in the last five years. One of the largest demographic groups is mainland Chinese.

Park officials said that some buses ferrying Chinese visitors last year caused problems with passengers rushing to make contact with wildlife and trampling geothermal features. Mayhem prompted Wenk in March to draft a letter to 85 different tour operators warning tour leaders that their clients are expected to obey codes of conduct.

Visitors are required to maintain at least a 25-yard (23-meter) distance from bison, elk, and other animals, and at least a hundred yards (91 meters) from bears and wolves. Yellowstone has prepared “safety cards,” spelling out the rules of wildlife watching, in English, Spanish, and Mandarin and has asked that they be prominently displayed in buses.

Some busloads of passengers did not use restroom facilities. “I was shocked to get reports last year of bus drivers passing out toilet paper and allowing their passengers to go into the forest,” Wenk writes.

For the first time ever, Yellowstone has hired a full-time social scientist whose job, in part, will be to help educate visitors about what is expected when they enter the park.

Few are more familiar with the consequences of bad tourist behavior than Yellowstone historian Lee Whittlesey, author of the best-selling book, Death in Yellowstone: Accidents and Foolhardiness in the First National Park. The tome chronicles nearly 300 human fatalities ranging from bear maulings and bison gorings to people scalded in hot springs, falling off cliffs, being struck by lightning, and eating poisonous plants.

“People come here wide-eyed and excited but they don’t read the signs and don’t listen to the cautionary messages of rangers,” he says. “The first animals they see they go crazy. All four doors on the vehicle fly open or the bus stops and they fly out chasing the animals. Not good.”

He has concern for the safety of people but he sympathizes with the startled park animals.

“For a lot of visitors, this is an alien environment because so much of the rest of the country, so much of the rest of the world where they come from, is manicured, manipulated, tamed and artificial. Their idea of a park is Disneyland,” he says.

Yellowstone, with more grizzlies, wolves, and bison on the landscape than a century ago, demands a different kind of thinking, one that is explored in David Quammen’s cover story for the special May 2016 Yellowstone issue of National Geographic magazine.

“It’s not our job to control what the animals do,” Whittlesey says. “If we did that, this place wouldn’t be wild. Yellowstone isn’t a zoo. You can get hurt. We have big animals that can kill or eat you.”

In recent days, some have speculated that maybe the bison calf plucked from the roadside could have already been abandoned by its mother. Wallen says it’s certainly possible but more likely its mother was nearby out of sight. If that were the case the park visitors were lucky she wasn’t in closer range or they might have taken a horn in the side.

After the calf was euthanized some on social media criticized Yellowstone for ending its life.

“People don’t like to see animals die but the reality is that if the calf had been re-released it probably would have lasted 15 minutes before a wolf, coyote, or bear preyed on it,” Wallen says, noting that the park would then have been ridiculed by some for not intervening to prevent the harsh reality of nature from taking its course. (Learn more about bison, our national mammal.)

Wildlife Isn’t Yellowstone’s Only Danger

On Monday a group of young Canadian filmmakers came under investigation after they brazenly hiked off the boardwalks at Grand Prismatic Spring, Yellowstone’s largest and most spectacular colorful hot spring that contains sensitive crusts and organisms specially adapted to its superheated water.

Two years ago, a Dutch tourist was fined a thousand dollars and had to pay another $2,200 in restitution after he crashed a drone into Grand Prismatic. The remote-controlled aircraft sunk into the rainbow-hued pool, prompting geologists to worry that the wreckage could harm the natural marvel by plugging its vents. Months before that, a German visitor flying a drone was fined and a tourist from Oregon was also cited. It prompted Yellowstone to order all drones grounded.

Fortunately, it is the exhibitionist behavior of some park visitors who post their misdeeds on social media that allows officials to become aware of their transgressions.

“I don’t want to sound harsh, but the march of stupidity carries on and most of the time it’s not owed to maliciousness but ignorance,” Whittlesey says. “This isn’t a place that always forgives people doing dumb things.”

For bison biologist Wallen, he’s seen plenty of videos where bison decide they’ve had enough. He always knows there’s trouble brewing when the big ungulates get an incensed look in their big eyes and their tails start snapping.

“We’re glad people are passionate about this place and enjoy it as much as they do,” he says. “At the same time, there are a lot of people out there in the world who came to Yellowstone and were lucky they didn’t get hurt. We want the park to be safe for the animals who live here, too.” (See why Yellowstone's grizzlies shouldn't be hunted, says the author.)