The American black bear
Why do black bears have different fur colors? Scientists suggest that it is a natural genetic phenomenon that allows bears to adapt and survive best in their climates and habitats. For example, in dense deciduous forests in the Appalachians, bears are primarily black -” appropriate camouflage for dense thickets and underbrush. In dry western regions, black bears are predominantly brown or cinnamon in color, reflective of the rocky, more sparsely vegetated landscape. The American Bear Association notes that only 1% of black bears in Pennsylvania are brown, while 90% of black bears in Yosemite National Park are tan, light brown, or cinnamon.
The American black bear
Research also suggests that fur color may be influenced by heat; black absorbs and retains heat more efficiently than does brown or blonde. Thus, black is more predominant in colder climates, while lighter shades are more prevalent in warmer and drier climates. Melanin is the pigment that causes the “blackness” of bear fur, and there is also evidence to suggest that the more melanin in the coat, the more abrasion-resistant it is. Thus, bears living in more dense cover benefit from more melanin-rich (black) fur.
The American black bear
The Pacific Northwest has the widest array of black bear colors. Perhaps the most interesting is the vaunted Kermode or “spirit” bears found on Gribbell Island in British Columbia. They have a striking white coat caused by a recessive gene, and are found in small pocket populations. While albino bears also exist throughout the black bear’s range, spirit bears are not albinos. Spirit bears are the rarest color phase of all black bears.
The American black bear
Black bears can change colors throughout their lives. Most commonly, young bears in brown or cinnamon phases will get darker (black) as they reach adulthood. Bears also molt in summertime, changing the appearance of their fur to a lighter sheen. As the season cools, the full coat returns in its natural color. It is also possible for the sun and landscape to bleach the appearance of a bear’s fur.
The American black bear
Some black bears have visible white “blazes” on their chests. Blazes are very common among young cubs, and researchers believe this may be a natural means for bears to identify individual animals. For example, a sow bear can recognize her cubs by the distinctive chest blazes in their fur.
While considered less dangerous than their grizzly bear counterparts, black bears are not to be underestimated. They have an uncanny sense of smell and good eyesight, and are extremely powerful. It is easy for some people to confuse a large brown or cinnamon phase black bear with a grizzly. The most notable differences are that black bears have smaller heads in proportion to their bodies, and do not have the distinctive grizzly hump at the shoulders. Black bear claws are also more curved, making them extremely efficient tree climbers.
Sources: The American Bear Association, americanbear.org; The Bear Planet, bearplanet.org.
Photo credit: Don Jones (except in slide 4)
