These images show two vulnerable Himalayan black bears - a father and his son - kept in cramped and barren cages in a Russian zoo as the younger bear risks being badly mauled by starting to spar with his dad.In the wild, the cubs would be raised by the mother away from the father, who is a danger especially for older males, but in the cramped and confined cage, the father and son are forced together and increasingly engage in these sparring activities that look like harmless fun – but it is actually dangerous to keep black bear fathers too close to their offspring.(@Barnaul Zoo/Newsflash)