The correct scientific name for the species is “brown bear,” but usually only the coastal bears in Alaska and Canada are referred to as such, while inland bears and those found in the lower 48 states are called grizzly bears.
Getting to Know the Grizzly Bear
Written by US Fish and Wildlife Service
Lewis and Clark first reported observing grizzly bear – which Clark described as “white bear” in his diary – during the fall of 1804, during their expedition across what is known today as North and South Dakota. With the help of Native Americans, who knew the majestic grizzly as “Hoh-host,” Clark correctly distinguished it from the black bear, or “Yack-kah.” The information documented in the journals of Lewis and Clark provided the first scientific data on the grizzly’s primitive range, habitat, and physical characteristics.
During the early 1800’s, grizzly bears ranged throughout western North America, across vast stretches of open and unpopulated land. In the continental United States alone, an estimated 50,000 of these bears roamed between the Pacific Ocean and the high plains of the West. But when pioneers moved in, they wiped grizzlies out. Many of the bears perished. As European settlement expanded over the next hundred years, towns and cities sprung up, and habitat for these large omnivores — along with their numbers — shrunk drastically. Today, with the western United States inhabited by millions of Americans, only a few small corners of grizzly country remain. While self-sustaining populations of grizzlies — also called brown bears — still inhabit Alaska and Canada, only about 1,400 wild grizzlies survive in the Lower 48. In 1975, the U.S. Fish and Wildlife Service listed the grizzly bear as a threatened species in the Lower 48 States, placing the species under federal protection. Grizzlies remain in only five ecosystems in the States of Montana, Idaho, Washington and Wyoming — designated as the North Cascades, Selkirk, Cabinet-Yaak, Northern Continental Divide, and Yellowstone recovery zones. See the “Current Status of Grizzly Populations” on this website’s menu for more information.
The grizzly bear of the northern Rocky Mountains is Ursus arctos horribilis, one of two recognized subspecies or varieties of the bear. (The other subspecies, var. middenforffi, is found in Alaska’s Kodiak Islands and is commonly known as the “Kodiak” or “Alaskan Brown” bear.)
The common name grizzly is derived from the term “grizzled,” which refers to hair that is either flecked with gray at the ends or is a mixture of gray and darker colors. Many grizzly bears show this coloring on their coats as white flecking on the ends of dark hair. Black bears never have this flecking or grizzling of their hair. It is from this “grizzled” nature of the coat that the title “silvertip” is also applied to the grizzly bear. The “grizzling” of the grizzly bear’s coat leads to many color patterns among these bears. Grizzlies may be pale – almost luminous blond to reddish blond to light brown to darker brown to even black. Grizzled hairs occur mainly on the back and shoulders, thus, from a distance, the grizzly often appears to have darker legs and light upper parts.
Grizzly bears are one of the slowest reproducing land mammals. Females do not typically reproduce until they are four or five years old. Grizzly bears mate between May and July, but the female’s body delays implantation of their eggs in the uterus until October or November. If the female has not gained enough fat over the summer to survive and raise cubs, implantation may not occur. A grizzly’s ability to garner enough quality calories through the summer is not just crucial for her survival, but also for her reproductive ability.
Mother bears rear cubs for two to three years. Males do not help raise the cubs. In fact, males can be a danger to the cubs, so females often avoid male grizzly bears while rearing their cubs.
Mating Season: Early May through mid-July
Gestation: Anywhere from 180-270 days, including delayed implantation.
Litter Size: 1-4 cubs, but average is 2-3