Home, home on the range? Not so much for an elk herd near Vail, Colorado. Unfortunately, the number of elk among this group has dropped off dramatically, and it could worsen if outdoor enthusiasts continue scaring them away.

In February, researchers flew over unit 45 where the elk reside and counted just 53; at one time there were more than 1,000. The herd makes its home between 7,000 and 11,000 feet on hills and at the top of the Colorado Rockies.

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“Very few elk, not even many tracks,” the researchers noted. “Lots of backcountry skiing tracks.”

Wildlife managers say growing numbers of hikers, mountain bikers, skiers, ATV and motorcyclists are among those causing the herd population to shrink. Visiting U.S. parks and wilderness areas for recreation has become a popular pastime; Yosemite, for instance, reports around 5 million people visit annually.

Bill Alldredge, a retired wildlife professor at Colorado State University, believes the reason the elk and their calves have died off is because of the increase in outdoor recreational enthusiasts hitting the trails near unit 45. In Colorado, a hot-spot for outdoor fun and trail use, visitation to the elk area has more than doubled since 2009; reports say about 170,000 people visit per year.

elk looking toward a passing car

According to Bill Andree, a wildlife manager for Colorado Parks and Wildlife’s Vail district, unit 45 is busy 24-7, 365 days a year. Even night trail use in some sections has increased by 30 percent in the past 10 years.

Andree began studying unit 45 in the 1980s because of the rise in ski resorts and trails systems. He researched how humans impacted the elk calves by sending hikers into the calves’ area. About 30 percent of the elk calves died when their mothers were disturbed, but when the outdoor enthusiasts stopped, the number of calves returned.

Why calves die after being disturbed by human activity isn’t crystal clear, but some researchers say it could be because the mothers get scared by people and dogs passing. If mothers run too far for their babies to catch up, this may result in starvation and possible attacks by other animals.

Signs have been posted to prevent explorers from disturbing elk habitats, but while a majority of nature-lovers obey, the fraction of people who cross those lines continue to cause stress to elk populations.

Via The Guardian

Images via Bob Denaro and Mark Byzewski