Greater Yellowstone Elk-wolf Study Shows Elk Having Fewer Calves

Wolves have caused elk in the Greater Yellowstone Ecosystem to change their behavior and foraging habits so much so that herds are having fewer calves, mainly due to changes in their nutrition, according to a new study published by Montana State University researchers. During winter, nearly all elk in the Greater Yellowstone Ecosystem are losing weight, said Scott Creel, ecology professor at MSU, and lead author on the study which appears in the Proceedings of the National Academy of Sciences. "Essentially, they are slowly starving," Creel said. "Despite grazing and browsing during the winter, elk suffer a net loss of weight. If winter continued, they would all die, because dormant plants provide limited protein and energy, and snow makes it more difficult to graze efficiently." With the presence of wolves, elk browse more - eating woody shrubs or low tree branches in forested areas where they are safer - as opposed to grazing on grass in open meadows where they are more visible, and therefore more vulnerable to wolves. Browsing provides food of good quality, but the change in foraging habits results in elk taking in 27 percent less food than their counterparts that live without wolves, the study estimates...ScienceDaily