2017-08-04 09:40:03
Trilobites: Mountain Goats on Your Trail? They Like You, and Your Urine

09:40, August 04 130 0

A few years ago, employees at Glacier National Park in Montana noticed that mountain goats were hanging out — even sleeping — far away from cliffs, and spending much of their time near humans. Researchers who investigated this atypical behavior determined that where there were people, there were fewer predators. Also where there were people, there was pee.

Combined, these phenomena afford mountain goats two prized essentials: safety and salt. “You can’t beat that. It’s like vacation for goats,” said Wesley Sarmento, who led the study, published in the journal Biological Conservation last month, as a master’s student at the University of Montana.

The study is part of a growing effort to understand how national parks, though often thought of as pristine havens, can affect local ecology and wildlife, sometimes in harmful ways.

First, a bit about mountain goats: They have many foes, but gravity is not one of them. Snowy-colored and sure-footed, they can scale nearly vertical rock faces, jump 12 feet in one leap and chill out at precipitous elevations of up to 13,000 feet year-round. Their skills help them evade less acrobatic predators, like bears, wolves and cougars.

Mountain goats also love salt. They are known to travel more than 15 miles to lick natural salt deposits, which provide essential nutrients. But human urine is packed with minerals from our salty diets, and mountain goats will forgo those journeys if there is a lot of urine around. As a result, many a hiker has strayed off-trail to tinkle and found mountain goats lurking, eager to lick a rock or eat a plant drenched in fresh, life-sustaining urine.

Over three years, Mr. Sarmento and his thesis adviser, Joel Berger, a scientist at the Wildlife Conservation Society and a professor at Colorado State University, closely observed mountain goats near and away from tourist-heavy areas in Glacier National Park, noting where the goats got their minerals and how cautiously they behaved. One of these sites, Logan Pass, receives about 3,500 visitors a day. At peak hours on a popular hiking trail there, a goat might encounter 400 people an hour.

To test how mountain goats reacted to predators, Mr. Sarmento dressed up as a bear and presented himself to goats at both tourist and backcountry sites, noting their responses (yes, this is a credible technique used in ecology research). He also took advantage of a nearby wildfire that led the park to close Logan Pass for a week in 2015, to see what goats did when there were no tourists.

The scientists determined that while predators and pee both were at play, predators seemed to be driving goats’ behavior. Mountain goats that stuck around humans were generally not as vigilant as their backcountry counterparts. When presented with the bear mimic, backcountry goats fled, on average, 600 feet farther than those near people.

During the wildfire closing, goats that usually hung around Logan Pass returned to the cliffs. There was still plenty of urine around — goats can lick the same patch for up to 10 days — but the researchers’ predator cameras picked up more bears at Logan Pass that week than they had over two years, suggesting the promise of salt was not worth the risk. Once people returned, the goats did too.

The researchers also noted that goats habituated to people stopped their annual migration to a natural mineral lick. “If mother goats aren’t passing that behavior onto their young, they might lose a migration that has accrued for thousands of years,” said Mr. Sarmento, who now works for Montana Fish, Wildlife and Parks.

There may also be more instances of aggression if mountain goats get more comfortable around people, Mr. Sarmento added, noting that a mountain goat killed a hiker at Olympic National Park in Washington State in 2010.

Studies like this show how national parks must grapple with the conflicting mandates of preserving nature and providing recreation for visitors, said Laura Prugh, an assistant professor of wildlife at the University of Washington who was not involved in the study.

One thing visitors can do is minimize their interactions with wildlife in these spaces, she said. “It might make for nice photographs,” she said, “but it can really be detrimental in the long term.”