Female brown/grizzlies form close bonds with their cubs, nurturing, teaching, and protecting them for two to three years. Each cub is an individual with a distinct personality. I watched this family for two hours at close range. At one point, one of the cubs chased a playful red fox while the other clung close to mom. Both yearling cubs took turns nursing and grazing. Putting on enough weight, quickly, is vital to survival. Only one in ten cubs lives to mating age (4-7).