In the past, most of the grizzly bears in and around Yellowstone National Park entered dens by mid-November. Recently, however, den entrance dates seem to be getting later as late fall temperatures are warmer.
Grizzly Bear Characteristics
Grizzly bears (Ursus arctos horribilis) have concave faces, a distinctive hump on their shoulders, and long claws about two to four inches long. Both the hump and the claws are traits associated with a grizzly bear’s exceptional digging ability. Grizzlies are often dark brown, but can vary from blonde to nearly black. The long guard hairs on their backs and shoulders frequently have white tips and give the bears a “grizzled” appearance, hence the name “grizzly.”
Grizzlies live in and use a variety of habitat types, playing important roles in each one. This makes them an “umbrella species,” meaning that when we protect them and their habitat we also protect many species. Grizzly bears can also help ecosystems by distributing seeds and nutrients through their scat, and perhaps regulating ungulate populations.
Grizzly bears are omnivores, and their diet can vary widely. They may eat seeds, berries, roots, grasses, fungi, deer, elk, fish, dead animals and insects. In the late summer and early fall, grizzlies enter hyperphagia, a period of 2 to 4 months when they try to take on more calorie-rich food to put on weight for winter denning. During this time period they can gain more than three pounds a day!
Did You Know? Grizzly bears use “rub trees.” These are trees where they scratch their backs, leaving scent and hair. Biologists can use these trees to collect DNA from many bears living in the area.
Neuroanatomy of the Grizzly Bear
Written by grizzlybrain.webs.com
The neuroscience that forms the basis of the central nervous system and autonomic nervous system in grizzly and black bears has been correlated with gross brain and spinal cord anatomy. Explicit attention has been directed to the special senses, particularly olfaction. We analyze the neuro-physiological function of the Grizzly Bear brain using MRIs, CT Scans, and arteriograms. In addition, we include histological staining of grizzly bear brain sections.