Extinction means the end of a species - forever - and is a normal event in the evolutionary process. Of all species that have ever existed, 99.9% are now extinct. During the last 500 million years, the normal extinction rate has been punctuated by five massive, worldwide extinction events. These events were associated with large scale changes in Earth's environment caused by natural catastrophes, such as the impact of asteroids or comets.
Today, many scientists believe the extinction rate is at least 40 times the normal rate. Much of this increase is blamed on environmental changes caused by a growing human population. Since 1950, Earth's population has doubled to 6.1 billion people.
|Coyote, Black-billed Magpie, Deer|
My hand in comparison to a grizzly bear front paw (right) and a grizzly bear back paw (left). Grizzlies are rare in the lower 48 states, but black bears live in most of the forested areas of North America. Black bears and grizzlies can live in the same area and can be very close in size and color, so there is often some confusion between the two bears. Black bears are not always black, and grizzly bears are not always brown. Both bears vary in color from blond to black. To best distinguish the two types of bear, look for the prominent shoulder hump and long claws on the grizzly bear, or the tall, pointy ears, short claws on the black bear.
Two hundred years ago, more than 50,000 grizzly bears roamed the lower 48 states. Expanding human settlement and uncontrolled hunting and trapping caused grizzly populations to decline. By 1975, with fewer than 1,000 grizzlies south of Canada, and fewer than 200 in the Greater Yellowstone region, the grizzly was listed as threatened under the Endangered Species Act. During the next four decades, federal and state agencies, private landowners, and conservation groups rallied to protect bears and their habitat, and to educate people about living with bears. As of 2017, more than 700 grizzly bears inhabited the Greater Yellowstone Ecosystem and the recovery criteria were met to remove grizzlies from the Endangered Species List.
|Great Horned Owl|
A wolf pack centers around a family group consisting of an adult pair and their offspring of various ages. All members of a pack care for the young. After they are weaned, pups are fed with meat regurgitated by their parents.
People hold strong and varied emotions about wolves. Facts, fears, and folklore become intertwined to shape people's perceptions. The Christian church in Europe has used the wolf to symbolize evil. In contrast, Native Americans have generally revered wolves as powerful, sometimes sacred animal spirits. The many visions of the wolf are reflected in art and artifacts from different cultures.
Another wolf ruled the Ice Age. The dire wolf was more common than the gray wolf in Pleistocene North America. It most likely preyed upon ancient relatives of modern horses and bison. Both the dire wolf and its prey became extinct about 10,000 years ago. Wolves ranged widely through North America in pre-Columbian times.
The wolves' habitat and natural prey decreased with the westward expansion of Euro-American culture. These settlers viewed wolves and other predators as nuisances. By 1950, people had exterminated nearly all wolves from the lower 48 United States. Attitudes toward predators gradually changed. People began to view the wolf as an important piece of nature's puzzle. Wolves returned naturally to parts of their former range, but good habitat was scarce. The Greater Yellowstone region was identified as one of the few places wolves could be restored and survived.
Since wolf introduction in Greater Yellowstone, many people rejoice that the wolves have reduced elk populations and protected open valleys from overgrazing. But the number of elk killed has been more than expected in some areas. Many local outfitters and hunters worry that the wolves will end up killing all of the elk. Today the debate is still strong between people who view wolf restoration as a great ecological success and those who view wolf restoration as a terrible problem. Wolves are protected in the Yellowstone and Grand Teton National Parks, but are managed according to different rules in each of the three bordering states (Wyoming, Montana, Idaho) outside the parks.
Wolves were returned to Greater Yellowstone in 1995. They have thrived since their return and have restored Yellowstone to a more primitive state similar to pre-Columbian times. Wolf restoration has created challenges and concerns for some people, especially local hunting outfitters, ranchers, and other commercial interests. It has also created a thriving new economy built around wolf-watching.
|Camp Monaco Tree|
|Grizzly Bear & Wolverine|
|Snakes of Dirt|
The crest of a long series of mountain ranges that extend from Mexico through the western United States into Canada is called the Continental Divide. Depending on which side of the Divide rain and snow falls, small streams gather the runoff and guide it toward either the Atlantic or Pacific Ocean.
|The Teton Range|