Bears in Yellowstone National Park
“Bears are made of the same dust as we, and breathe the same winds and drink of the same waters. A bear’s days are warmed by the same sun; his dwellings are over-domed by the same blue sky, and his life turns and ebbs with heart pulsating like ours, and was poured from the same First Fountain.” —John Muir
The grizzly and black bear both call Yellowstone National Park their home. While 90 percent of the bears’ diet is vegetation, both types of bears are omnivores. Grizzly and black bears enjoy a rich variety of food within the park boundaries: grass, berries, fruits, tree cambium, bird eggs, nuts, insects, elk calves, fish, and carrion (including elk and bison carcasses).
In late spring, bears prey on newborn elk calves until the calves become too fast for the bear to catch. Also in spring, Yellowstone’s cutthroat trout swim up streams to spawn and the bears have a feast! Bears are known to fish in 36 of Yellowstone Lake’s tributaries.
Grizzly Bear (Ursus Arctos)
A grizzly bear can weigh in between 325-600 pounds, almost twice as large as a black bear of the same age and sex. This large, brown bear with a distinctive hump on its shoulders originates from Eastern Siberia and is related to the Russian Brown Bear. With their long curved claws and strong shoulders they are ideally suited for digging. Grizzlies raid squirrel caches and eat the seeds of the white pine cones and they also feast on roots, ants, and even small rodents such as pocket gophers.
You are most likely to catch sight of a grizzly bear at dawn or dusk out in the open meadow areas. Approximately 400-600 grizzlies make their home in the Greater Yellowstone Ecosystem. They usually live between 12 to 20 years, though occasionally a grizzly will survive into its late 20s.
Even though they are mostly solitary creatures, grizzly bears have a strict social hierarchy. Adult males take over the best bear habitats and food sources. Next in line are mature females with cubs and then other single adult bears. Younger bears who are just learning to live on their own are the lowest on the totem pole, which makes them the most likely to have to "make a living" in poor habitat or in areas closer to developed areas.
Late fall marks the time when the bears in Yellowstone begin to find and dig their winter homes. Grizzlies often dig or create their own dens and may move a huge amount of material in their construction. Both grizzly and black bears tend to choose north-facing slopes for their dens. Some wildlife biologists believe this may be because such slopes collect more snow, which serves as extra insulation for the den.
Grizzly cubs weigh about one pound at birth and alternate between sleeping and suckling their mother’s milk. Both black and grizzly bears give birth to litters of 1 - 4 cubs. Grizzly cubs may stay with their mother for as long as 3.5 years but usually separate at two and a half. When the female grizzly is ready to mate again, she will drive her cubs away. This usually happens during the cubs’ second summer. Female cubs often establish their own home range fairly close to their mother’s, but male cubs must search farther to find a new home.
Black Bear (Ursus Americanus)
Black bears are North American natives and they can weigh in between 135-315 lbs. You will find that a black bear prefers the forested areas of Yellowstone park. Their short, curved claws are especially suited for tree climbing. They eat a similar variety of food to the grizzlies but they do not dig for tubers or roots like the bigger bear. Black and grizzly bears will also eat army cutworm moths that summer on high-elevation slopes.
These moths are one of the highest sources of protein available for a bear throughout the year.
The black bear is more likely during the winter months to curl up and hibernate in an existing hole or cavity for their den. Cubs are usually born during their mother’s hibernation period. Imagine going to sleep alone for four months and waking up with several new children!
The mother becomes semi-conscious during the birth, but after delivery she continues to sleep for another two months. Born blind, toothless and nearly hairless, black bear cubs weigh in at just half a pound and they survive on their mother’s milk until they emerge in early spring. Black bear cubs usually separate from their mother the following spring.
Myths And Legends
Bears have fascinated humans since the earliest times. Today people see the bear as everything from a cuddly stuffed animal to a walking nightmare.
In Native American cultures there are many tales of the she-bear or bear family adopting a human child and raising it as their own. Nearly all the Native North Americans revered the bear, referring to it as
"Grandmother" or “brother." Some tribes hunted it for its meat, hides and claws, or to display skill and bravery; however, others refused to eat bear meat, feeling it was akin to cannibalism.
A Native American legend tells of a great bear awakening from its long winter sleep and racing across the sky. Pursued by hunters through the northern horizon, the bear is wounded, and as it rears up in the autumn sky, it falls upon its back. The great bear’s blood seeps from its wounds onto the earth and stains the leaves red. Through the winter the Great Bear lies upon its back, only to be restored the following spring. The story of this hunt explains the existence of the Big Dipper constellation (the stars of the handle being the warriors and the cup being the bear itself).
The Future For Bears In Yellowstone Park
For hundreds of years bears have roamed the Yellowstone ecosystem surviving and flourishing on a rich variety of natural foods. With the great influx of human visitors to the area in the late 19th century these great opportunistic omnivores, have happily made easy meals of human food and garbage.
This has created many bear-human conflicts in the past. Since 1970 Yellowstone Park has implemented an intensive bear management program with the objectives of restoring the grizzly bear and black bear populations to subsistence on natural foods and reducing bear-caused human injuries and property damages.
Now there are strictly enforced regulations that prohibit the feeding of bears. All garbage cans throughout the park are made bear-proof and all garbage dumps within the park are closed. The 1970 bear management plan was highly successful in reducing the number of bear-human conflicts occurring in the park. Following implementation of the program, the number of bear-inflicted human injuries and bear-caused property damages in the park declined significantly.
Today, an average of less than one bear-inflicted human injury and only 12 bear-caused property damages are reported each year. There are more people hurt by bison than by bears each year in Yellowstone. Park regulations state that visitors must stay at least 25 yards away from bison or elk and 100 yards away from bears.
While the bears enjoy their protected habitat within the boundaries of Yellowstone they do roam in areas outside of the park. Their habitat outside of the park is threatened and altered by large scale logging, resort and subdivision development and human presence.
Global warming and the changing climate in Yellowstone Park may threaten some of the bears’ usual sources of food. The white bark pines, (bears enjoy its seeds in the autumn months) are suffering due to the pine beetle infestations. It is believed by some scientists that bears will sample new foods in small quantities so that when their usual source is scarce they will have alternatives.
Today, the Grizzly bear population in the park is continuing to grow by 4-7% a year. After over thirty years on the U.S. Fish and Wildlife service threatened/ endangered species list the grizzly bear was removed from the list in April of 2007. Conservationists and government bodies worked together to protect their habitat and the species has made a remarkable recovery…some call it the greatest conservation successes in the history of the United States.
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