Secret behind grizzly bear's tree rubbing antics revealed

The mystery behind the tree rubbing antics of North America's grizzly bears may at last have been solved.

A few select trees are used by grizzlies to perform strange rubbing rituals, but for years the reasons for this behaviour have baffled ecologists.



Now, a study suggests that male grizzlies seeking mates are marking the trees to communicate with other males - possibly to dodge deadly bear battles.

Many theories have been put forward as to why grizzlies are rubbing these trees: some thought they were using them to scratch an itch, others that they were trying to rub on tree sap to repel insects, while some thought they were using the trees to attract mates.