The Great North American Black Bear
The North American black bear, scientifically known as Ursus americanus, is a type of bear that is indigenous to Northern America. Subspecies such as the Ursus americanus luteolu (Louisiana black bear) and the Ursus americanus floridanus (Florida black bear), have small populations and are found in Louisiana and Florida respectively. However, the North American black bear, which has an overall population of approximately 600,000 is distributed across Canada and Mexico, and can be found in at least 40 states in the United States (Powell, Zimmerman, & Seaman, 1996). Although it historically occupied almost all forested regions across North America, most of its habitats have been destroyed by human expansion, particularly within the United States. As omnivores, black bears exhibit extreme adaptability and variation in terms of habitat types, which is primarily the reason for their large numbers, and surprising ability to exist in two environments, which are forests and tundra.
The life cycle of a Nothern American black bear begins during the mating season between May and July, typically from early June to mid July, with most female bears reaching sexual maturity as early as 3 or 4 years, and the males between 5 and 6 years. However, this stage is dependent upon the availability of food, and can even occur as late as after 5 or 6 years. Although females can produce litters of between 1 to 5 cubs every 2 or 3 years, this interval may widen to 4 years in habitats where food is scarce. The cubs are then born during hibernation between January and February weighing, slightly more than 225 grams and only about 15 to 20 centimeters long. At birth, the cubs are blind and hairless and have their mother’s breast milk as the sole source of food; nursing while their mother continues to hibernate until spring. The mother then leads the cubs out during spring and weans them between July and September before they are ready to hibernate for the winter. By this time, depending on the availability of food, the cubs will have developed a number of hunting skills and put on a significant amount of weight. At the end of the second spring, the mother usually drives away the cubs and is ready to breed again (Craighead, 2000).
The North American black bear is omnivorous and has a digestive system that is similar to that of human beings.
Grizzly bears live in a variety of environments .All of which includes dense forests, subalpine meadows, open plains and arctic tundra . In the past though, they could be found from Alaska to Mexico, and from California to Ohio. Though Nowadays there are efforts trying to make it so grizzly bears can make a comeback and the wild, and all of their efforts are proving to be working, there are 4 times as many grizzlies in the wild as there were in 1975, at
Nature, it is everywhere, everyone uses it. Quite often, however, people abuse it, such as with humans’ impact on grizzly bears. Grizzly bears are important to the environment because they have many useful purposes for the environment: “they provide an “umbrella” for the environment because they require such large home ranges.” (savethegreatbear.org/CAD/Grizzly.htm) The Grizzly Bear is extremely vulnerable to changes in its habitat and food cycle. This allows humans to detect small changes in the environment, just by watching this amazing species. The Government of Canada needs to try harder to stop the poaching of grizzly bears in Canada.
The one way to keep bears and humans safe and living in the same environment is learning to understand them and being able to tolerate them. If people don’t do these things theses beautiful animals will begin to decrease in numbers. While there are a lot of black bears in Alaska, an estimated 100,000, hunters believe that you can just hunt and hunt and the population will decrease to average, but the plans of some hunters seems just over the top of making these bears go on to the endangered species list. But with the help of people and cooperation the Black Bears will continue to live in Alaska.
The phasocolarctos cunereus, also known as the koala bear, which was derived partially from the wombat and the sloth, does not play a huge role in the environment, but more or less a complex role that benefits the rest of the environment(New World Encyclopedia). Although the koala bear sleeps for nearly twenty hours, and spends around four hours or more eating, this benefits the rest of the environment and is part of the role it plays in the ecosystem. These interesting marsupials fear the grounds and also spend most if not all of their life in trees or high grounds and try to avoid the ground level areas as much as possible. When it comes to eating habits and food they are pretty general and specific and stick to one main food which is the eucalyptus plant and a few other non-eucalyptus plants. Koalas, being very harmless and simple animals still have a fairly important role in maintaining the environment and live a very complex and interesting life even while sleeping for three quarters of their day.
Gauss’ Law states that no two organisms can occupy the same ecological niche without excluding the other, but what happens when man gets involved with nature and tries to introduce a species where it doesn’t belong which in turn provides a second organism to fill the same niche as the first? The results of human intervention have often been disastrous for the organism that we’re supposedly helping. Humans often times do not understand the complexity of the implications that are caused directly through our intervention. In 1974, the gray wolf was listed on the Endangered Species List, and in an effort to reestablish their populations, wolves were re-introduced into Yellowstone National Park, affecting Wyoming, Montana, and Idaho (Wyoming Wolf Management Plan, 2003). Between 1995 and 1996 thirty one wolves were reintroduced into Yellowstone and thirty five wolves into central Idaho. The wolf numbers exploded, leaving these western states with the problem of what to do with these wolves to prevent them from exceeding their carrying capacity and where to go from here.
Wolves have always been a symbol of the wild, free in spirit and roamers of the land. These animals are considered majestic and protectors of the wilderness. They have always roamed the western United States, although their population has fluctuated over time. Over the past 10 years wolf reintroduction into Yellowstone National Park has been a controversial topic to those of the United States. As of 1995, wolves have been reintroduced into the park. This has come with some strong opposition and yet has prevailed. The future of the wolf in Yellowstone park is now looking bright, although not certain since there still are those who want them banished again.
grizzlies will hibernate when there is a seasonal shortage of food, low environmental temperatures, or when there’s snow arrival. Grizzly bears hibernate five to seven months each year. The grizzly will enter into hibernation in October or November. During this time the grizzly bear must prepare a den and consume as much food as possible to last their hibernation period. While searching for a den the grizzly may travel many miles until it finds a suitable area that it likes. The dens are usually at elevations above 1,800 m (5,900 ft) on north-facing slopes. The reason why bears have to eat as much food as possible is because they need the energy from the food to last through the entire winter. They may eat up to 90 lbs of food per day, while trying to put on as much weight as possible. When it’s time for grizzlies to hibernate; will enter their den, and fall into a “deep” sleep. During this time the grizzlies won’t eat or drink; but instead they digest their stored up fat; (the fat used to last them through their entire hibernation.) The bear also will not urinate or defecate, but will reabsorb their urine and feces into proteins. The bear can use 25-40% of their body weight during hibernation; the bear’s heart rate and body temperature may also drop. By March or April, male grizzly bears usually emerge from the den and the females emerge in late April or May. When bears emerge from hibernation they’re
The Kermode bear is an interesting bear that’s endangered. It eats a healthy diet of salmon, found from the ocean, and berries ,found from brushes. It can either have a black coat of fur or some bears have white fur. The Kermode bear has many nicknames such as Spirit bear and ghost bear (Shoumatoff). Meanwhile they are rare which means we don’t want them to be exists because they are a unique species and they help the environment by eating salmon as their main source of food they take the “leftovers” and throw them in the grass this fertilizes the soil making it rich (Tweed).
Phillips, Michael K., Smith, Douglas W. The Wolves of Yellowstone. Voyage Press, Inc. 1996, pgs 25-30.
* Polar bears do not hibernate. Females will, however, dig dens in the snow and give birth to their cubs in the winter. The den provides insulation and protection until the sow and her cubs emerge.
These new hybrid bears are a good way for the polar bears to be around for many years to come. It allows to live long because they have two different genes in them and it also allows them to survive anywhere in the world because their fur is mixed. They have brown fur that allows them to be on land for a long amount of time and they have white fur which allows them to live in the snow and let them stay in freezing water for a long amount of time.
The female Black Bear is fifty to fifty-five inches in length and their tail can range from three to four inches in length. A female’s paws are also quite large at about eight inches in length. A smaller female weighs about two hundred twenty-five pounds, but a larger female can weigh up to four hundred fifty pounds.
According to the Alaska Department of Fish and Game, the brown bear is located all throughout Alaska, mostly in areas that allow them to seasonally hunt salmon (Alaska Fish & Game, 2010). This allows them to become larger and live in higher concentrations than the grizzly bear. The traditional brown bear and the grizzly bear are actually both classified as brown bears, despite having several differences in appearance. Brown bears are one of the most fascinating and powerful species in the Alaskan wilderness. Cubs are usually born during January or February, usually in groups of one to four (Alaska Fish & Game). A fully grown, male brown bear can weigh up for 1,500 pounds and be over 10 feet in stature (Alaska Fish & Game, 2010). Brown bears also have the ability to run at speeds up to 40 mph for short bursts of time (Alaska Fish & Game). All of these unique characteristics make many people upset that it is legal to hunt them. There are several groups that are working to conserve the brown bear population, particularly in Alaska, such as The Northern Forum’s Brown Bear Working Group (Fish & Wildlife Journal, 2010). The bear population in Alaska is thriving and is classified as a status of least concern, by the IUCN Red List (IUCN, 2010). Overall, the brown bear population faces no danger whatsoever.
The characteristics of the grizzly bear as a top predator also make it highly vulnerable to threats. Although it is an omnivore, because it relies heavily on salmon to make it through the winter, it is vulnerable to anything that impacts on salmon runs. It needs wide-ranging habitat and is slow to reproduce. As such, grizzly bears are considered not just a key species but also an ‘umbrella species’ because the protection of their habitats will result in an ‘umbrella of protection’ for a wide range of other species. The protected areas that have been set aside in the Great Bear Rainforest are not enough to sustain healthy populations of grizzly bear so it requires additional habitat set aside from logging. Trophy hunting of grizzly bears also continues to place their population at
Breeding usually takes place in April to June. Polar bears reach breeding maturity at three to five years of age.