You know the sign that says “Don’t Feed the Animals?” Apparently there needs to be one that says “Don’t Put the Animals in Your Vehicle.”

A newborn bison was euthanized after two tourists at Yellowstone National Park put the calf in the back of their SUV and transported it to a park facility. The visitors believed it was freezing and dying. The visitors were cited by the Park Service.

Placing the calf in the vehicle was dangerous activity because adult animals are very protective of their young and will act aggressively to defend them, the Park Service said.

In addition, interference by people can cause mothers to reject their offspring.