Many mammals, like the bighorn sheep, have lost or are in the process of losing their winter coat. Before winter arrives, they grow thick fur to survive the long winter. And for the summer, so they don’t overheat, they lose their winter coat. During hikes, you will often come across clumps of fur that have fallen off the animals. Some birds will use the fallen fur for the nest building. I have seen chickadee take fur from dry wolf scats to help build their nest. Certain mammals not only grow thicker fur for the winter but, like snowshoe hares, arctic foxes and some weasels go from a darker summer coat to white for the winter. For the prey, it makes it easier for them to hide in the snow and for the predators, it makes it easier for them to hunt. For some of the mammals, they will have a topcoat called "guard hair" and a much thicker layer of underfur. This adult male bighorn sheep was at the bottom of the valley looking for minerals to lick, and its mates who had already gone back up the slopes for safety.
