“Some itches just have to be scratched,” says British naturalist Sir David Attenborough in BBC’s Planet Earth II. And it seems that rubbing up against trees is a ‘bear necessity of life.’ Bears have favourite trees and will walk for miles just to rub their backs on them. They’re probably trying to shed excess fur or mark the trees with their scent for territorial reasons. Or they just really have an itch to scratch!
Many theories tried to explain this habit. Some believed females could do it when they were at the peak of their fertility, while others thought that bears just attempt to cover their backs in sap, employed as insect repellent.
But a new two-year research of grizzlies in British Columbia employing digital cameras to gather information on which bears employed the trees for rubbing and when (the same rub trees can be used for generations, so there’s no difficulty in observing this behavior). Satellite equipment also monitored the bears’ individual movement.
“The cameras show that adult male bears are the most likely to rub trees, and the satellite telemetry tells us that males move from valley to valley in large loops, marking trees as they go, while looking for breeding females,” said author Owen Nevin, ecologist of the University of Cumbria.
Offspring also use the rub trees when a male is attempting to chase them away from their mother (males are known to kill sometimes a female’s offspring to force them enter the fertility period, so he can get a chance to fertilize her).
“They can visit the tree two or three times a day, sometimes within an hour of the big males, so it may be that smelling like him makes them safer – related animals smell similar and animals are less aggressive toward relatives,” explained Nevin.
Picture Credit : Google
