In a warming world, The decline of ice in Glacier National Park is revealing once buried salt licks. Now mountain goats and bighorn sheep are fighting over them.
As the namesake ice of Glacier National Park in Montana recedes, it is exposing once unavailable salt deposits coveted by animals far and wide. Both mountain goats and bighorn sheep are flocking to lick up sodium and other crucial nutrients they need to survive. A study published Monday in the journal Frontiers in Ecology and Evolution reveals how new winners and losers are emerging in the animal kingdom as rising temperatures alter the abundance and distribution of food, water and shade. Those crucial resources include salt licks. In a warming world, Many animals — including bats, primates and rodents — all go to great lengths for minerals they do not get from the rest of their diet. In Glacier National Park, months of observation reveal an undisputed victor in the Salt Wars: The goat. “We were surprised that mountain goats won,” said Joel Berger, a professor at Colorado State University and a senior scientist for the Wildlife Conservation Society who co-wrote the paper, in a phone interview. “Naively, I was just thinking, we’ve got two similar-sized species and they both live in these mountains,” he added. “And if everything was equal, then half the time we’d expect one to win and half the time the other.” In the vast majority of these high-altitude conflicts in Glacier, goats bullied sheep, the research team found. Most of the time, goats didn’t need to do much: Their presence alone was enough to shoo away the more passive herbivores.
The difference came down to attitude: Goats are simply more ornery. In a warming world, When warranted, the snowy-colored animals were willing to drop their heads and rush with their saber-like horns to get their way. “They are characteristically more aggressive,” said Forest P. Hayes, an ecologist and co-author who is pursuing a Ph.D. at Colorado State. In other battles over limited resources, size often does matter. Elephants in Namibia, for instance, usually get their way at watering holes, Berger’s past research shows. These kinds of fights are likely to intensify. As deserts dry and forests dwindle, water and shade will become scarcer in many corners of the world. Yet conflict between species over resources altered by climate change and other human disturbances “is a really poorly investigated arena,” Hayes said. “As we’re seeing potential shifts in resource availability and increases in scarcity, it’s increasingly likely that this is going to happen more often,” he added. “So understanding these conflicts and ramifications for interacting species is really important.” As the melting of mountain glaciers exposes salt licks high in the Rockies, the construction of roads through valleys covers up mineral deposits at lower elevations, raising the question: When should wildlife managers provide artificial salt licks? “We could manage some of these mineral resources more proactively for these populations,” Hayes said. But humans are already inadvertently introducing minerals in other ways. Animals risk getting struck by cars when they flock to roads salted during the winter. And goats in Glacier even hang around hiking trails to wait for campers to relieve themselves — and lick up the mineral-laced urine. The sure-footed climber has been observed hoofing up to 18 miles to get to a salt lick.