Bisons are oh-so-fluffy, walking, herbivorous animals that have long captured the world’s attention for their majestic dignity. Increasingly, however, they are also making headlines for dangerous clashes with tourists. This summer, we’ve already seen two high-profile bison in Yellowstone, both captured on video.

As a Montanan resident, professional bison conservationist, and neighbor to nearby Yellowstone National Park, I understand why people feel the urge to touch these massive mammals. They are a sight to behold – both undeniably cute and seemingly oblivious to our presence. But as a biologist, I assure you that they are well aware of our approach. They can and will react with lightning fast reflexes if we get too close.

Pamper me. The average NFL lineman weighs about 310 poundsand the fastest player in the league is clocked at approx 23 miles per hour† In comparison, a bison can weigh more than 2,000 pounds and run more than 35 miles per hour. But unlike in the NFL, there is no referee to whistle when a bison feels threatened. They charge until the threat has abated.

Recent and ongoing injuries from bison in parks and protected areas are tragedies for both humans and bison. Bison are not out to lure tourists, but with visit in Yellowstone and other parks on the rise, wildlife is feeling more pressure than ever before. About 4.86 million people visited Yellowstone in 2021, the busiest year to date. American travel has exploded recently as families trapped during the pandemic embraced their summer vacations. But that (understandable) wanderlust comes with a price. More generally, more than 55% of the land on Earth is shared by humans and wildlife. As our footprint extends even further into the wild, encounters between humans and wildlife increase, often leading to conflicts between humans and animals.

The broader problem may be that many of us no longer know how to relate to nature because we see ourselves outside of it. People are so used to experiencing wildlife through the lens of social media or a series of wildlife that we come to see ourselves only as spectators rather than participants when we enter real wild places. However, let me be clear: when we visit parks with free-roaming wild animals, we are a wild Surface. And we have no special rights or protections except our own common sense.

When you choose to disrespect the space of a bison, bear, or moose to get that social media selfie, it’s not only disrespectful — it’s dangerous. Humans may have evolved to think of themselves as apex predators, but they are in fact quite vulnerable.

For those who may still be traveling to parks this year, here’s a quick rule of thumb for bison: If you extend your arm and hold your thumb up, you should be able to cover the entire silhouette of every bison in the neighborhood. If not, you’re too close. This rule should keep visitors about 100 yards from a bison, a distance the animal can travel at 35 miles per hour in just under 6 seconds — if it so chooses. This doesn’t leave you much time to react, let alone coordinate your family’s response — as evidenced by recent events when a frightened child ran away from her parents in response to an attacking bison. At this distance, however, the bison will likely ignore you and prefer to attack a tasty patch of prairie grass instead.

It’s also important to note that a boardwalk or road will not prevent a bison from approaching or feeling anxious or threatened by visitors who are too close. One notable exception to the rule of thumb, although you should still respect a bison’s space, is traveling in a closed vehicle (motorcycles don’t count). However, I’ve even seen bison inadvertently damage cars that were too close, sometimes using a side mirror to scratch a hard-to-reach itch.