These bears have moves!
What appears to be opportunistic back scratching, with some dance moves thrown in, is more than likely a means of communication. As the bears scratch on tree they also leave their scent so other bears know who is in the neighborhood. This particular habit could come more often during mating season when boars are looking for a sow.
Researchers set up cameras on scent trees to record the happenings. The footage recorded seems more like a Saturday night disco show as these bears gyrate and jiggle while getting a good back scratching! Who said research was always boring? These bears are showing they have some serious dance moves.