Within the last 10 years a number of hybrids between polar bears (Ursus maritimus) and grizzlies (Ursus arctos) have been sighted in Canada. The two species usually do not come in contact, as their territories do not overlap. However, this has changed recently due to climate change.
From bears kept in captivity we knew that grizzlies and polar bears can produce offspring. Furthermore, their offspring was fertile. That begs the question whether brown bears and polar bears are separate species. Scientists claim that polar bears and brown bears first diverged as a species between 479,000 and 343,000 years ago. I thought a species is defined that only members of the same species can create fertile offspring. Nevertheless, they are both closely related.
So what’s all the fuzz about? I just read “The Blue Bear”, a “true story of friendship, tragedy, and survival in the Alaskan Wilderness”. Lynn Schooler writes about his adventures with Michio Hoshino, a famous Japanese wildlife photographer, who was mauled to death by a grizzly in Kamchatka. They both went on several trips in Southeast Alaska to find the evasive glacier bear. There are some pictures of bears with a silver-blue coat floating around. Maybe another species? Maybe just a color variation?
Not that important. I take it as another riddle of Nature.