Innate 'compass' allows deer to make collision-free escapes

PRAGUE, Czech Republic, June 7 (UPI) -- A team of biologists in Europe found herding deer rarely flee danger east or west. They almost always escape along a north-south axis when startled.

Over a period of 46 days, researchers monitored groups of grazing roe deer, Capreolus capreolus, at three hunting locations in the Czech Republic. They watched the deer during various times of the day, noting the direction of their grazing positions and escape routes.

When startled, the deer ran away from the observers on a north-south axis, rarely taking off the east or west. The deer also aligned themselves along a north-south axis when feeding, ensuring they were ready to make a break at the first sign of danger.

The consistent pattern of escape suggests the deer are governed by an inner compass that senses Earth's magnetic fields. Neither wind direction or the position of the sun influenced the deer's escape routes.

Their predictable exit strategy ensures the deer avoid collision in moments and panic and remain together as they seek the safety of new territory.

"This suggests that an important function of this behavior is to coordinate the movement in the group, to keep the common course of escape when frightened and to maintain the cohesion of the group," Petr Obleser, a researcher with the Czech University of Life Sciences, said in a news release.

The new research was published in the journal Behavioral Ecology and Sociobiology.