Other concerns include whether the increase in biking in natural areas could do more to displace grizzlies and other wildlife than hiking, because bikes cover so much more ground, Dr. Servheen said.

“The impacts are mounting because there are more and more mountain bikers and there is more pressure to go into these places with faster bikes and electric mechanized bikes,” he said. “The technology has exceeded our ability to manage it for the benefit of animals.”

Or to understand it. Some experts are raising questions about how fast-moving bikes startle not just bears, but elk, deer and other species, and disrupt their lives.

Dr. Servheen also believes that the sensational news of a grizzly bear killing a bike rider works against the bear from a public relations standpoint. “The response from many people to these kinds of attacks is that grizzly bears are dangerous and their habitat is a dangerous place,” he said. “It’s a cost the bears have to pay in terms of public support and the willingness to have grizzly bears around.”

Because the popularity of biking in these areas has grown rapidly, there is little research on its effects on wildlife. But there is a growing body of evidence that outdoor recreation of all kinds has serious consequences for wildlife.

“Over all we found a moderate to strong effect of recreation on wildlife across the board,” said Courtney Larson, who published a literature review of 274 studies in 2016 for her Ph.D. at Colorado State University and has just completed a meta-analysis on the effects of recreation.

The singular influence that mountain biking might have on the surrounding environment is not known, she said. “It’s a little difficult to tease out on its own because most of the time, mountain bikes use occurs on multiple use trails with hiking, mountain biking, dogs and horseback riders on the same trails,” Dr. Larson said.