The crash of horns as male bighorns (Ovis canadensis) battle for breeding rights can be heard echoing through the mountains during the autumn rut. With each contestant charging at full steam the closing speed can be 65kph. This is repeated four or five times an hour until a victor emerges. Horns weigh up to 14kg. Despite these bulky accessories the bighorn is an agile climber and good swimmer, leaping to remote ledges to escape predators such as wolves, bears and bobcats. The bighorn has always been hunted and, despite regulations to prevent its extinction, illegal poaching is a threat.