Vanuga says this dubious trend can be partly attributed to a few different factors: the number of people who are allowed in a park (nearly 3 million people visited Grand Teton National Park last year), the popularity of mobile devices and the selfie craze. "The selfies! It is mind-boggling what people will do," he says.
In nearby Yellowstone National Park, two bison recently attacked an Australian and a Taiwanese tourist. The park's spokesperson Amy Bartlett told The Guardian newspaper that in the case of the Australian man, "other people had crowded around the bison and it was 'already getting agitated' before he got out his camera."
The man reportedly - with electric notepad in hand - moved within 5 feet of the animal immediately before he was attacked.
Pat Owen is a wildlife biologist at Denali National Park in Alaska who focuses on wildlife management. At Denali, Owen told The Dodo, tourists are asked to abide by certain rules: a 300-yard viewing distance for both black and grizzly bears, and 25 yards for other wildlife species including wolves, sheep and caribou.
How often do tourists break these distance rules?
"Often," says Owen. "Very often."
In fact, she adds: "We are currently in the middle of a management nightmare."
A cow moose, Owen says, recently gave birth to twin calves. For reasons that might be based on food sources, or protection from predators, the cow and her calves are living inside the most popular campground in Denali, at the park's entrance.
The moose is extremely agitated, says Owen. "We've had two fairly serious injuries and I've lost track of the number of charges."
However, Owen says, despite the plethora of signs around the campground telling people to not disturb the moose, the three wildlife technicians rotating in and out of the campground - which is host to 150 sites - other support staff spreading the word about the moose, and a press release calling attention to the situation, tourists just do not seem to listen.
"I'm at my wits end," says Owen.
"It seems to me that people fall on either one side of the line or the other," she says, when describing the kinds of people who follow the park's rules - or do not. "They either get it, or they don't. Though even our most conscientious tourists are problematic," she adds.
One park worker was recently explaining to a tourist how the moose is charging people unprovoked, according to Owen. But the tourist insisted she had to get a photograph of the moose for her grandchild.
"The worker said, 'Okay, I'll take a photo of you so you can give it to your grandchild. Getting knocked down by the moose,'" says Owen. "I honestly don't know what it is."