NEW YORK (October 9, 2007) -- When it's time for moose to give birth in the Greater Yellowstone Ecosystem, they head to where it is safest from predators - namely closer to people, according to a new study by the Wildlife Conservation Society. Published in the Royal Society's journal Biology Letters, the study says that moose avoid predation of their calves by grizzly bears by moving closer to roads and other infrastructure prior to giving birth. Wildlife Conservation Society researchers tracked both moose and bears, finding that pregnant moose in Greater Yellowstone have shifted their movements each year for the past decade about 125 meters closer to roads during calving season, specifically to avoid road-shy brown bears, which can prey heavily on moose calves.
"Given that brown bears avoid areas within approximately 500 meters of roads in Yellowstone and elsewhere, moose mothers have apparently buffered against predation on offspring using roadside corridors," said Wildlife Conservation Society biologist Dr. Joel Berger, the study's author.
Berger also cited similar examples where prey species tend to use humans as cover from predation, including vervet monkeys in Kenya and axis deer in Nepal that avoiding big cats by staying close to ranger stations.
"The study's results indicate that moose and other prey species find humans more benign and hence move to humans for safety whereas predators do not because we humans tend to be less kind to predators," Berger added.
According to Berger, the results also reveal that national parks are not necessarily showcases of natural ecosystems, but instead can actually affect natural biological events in ways park managers haven't yet imagined.
Electronic copies of the study available