Dan Stahler

ScienceShot: 'Landscape of Fear' Not Impacting Yellowstone's Elk

Who's afraid of the big bad wolf? Not elk in the Greater Yellowstone area of Wyoming and Montana. That's the contention of a new study that disputes the notion that Rocky Mountain gray wolves, which were reintroduced into the region in 1995, have turned the once peaceful area into a "landscape of fear." After the wolves' return, scientists noticed that the aspen trees and willows began to recover, while elk numbers declined. Researchers attributed the trees' new growth to the wolves, because the elk could no longer blithely feed; they had to be vigilant and on the move. That added stress, some suggested, could also cause female elk to have fewer successful pregnancies, which would account for the elk population's dropping numbers. But a new study published online today in Ecology Letters suggests that the elk aren't that stressed by the wolves. After tracking both species in the region for three winters, and recording elk behaviors as wolves approached, the scientists argue that elk haven't dramatically altered how or where they feed. Only when wolves approach an elk within 1 kilometer (which happens on average about once every 9 days), as in the photo above, do elk pay close attention. The scientists also collected data on female elks' body fat and pregnancy rates and compared these to 19 other populations in the northwest that aren't hunted by wolves—there was no noticeable difference. Still, wolves do affect the elks' numbers in one way: They eat them.

See more ScienceShots.

Posted in Environment, Plants & Animals Animal Cognition