This lifeform is generally found west of the Continental Divide in North America The brown color will help identify this lifeform. This lifeform is threatened and might become extinct.
Grizzly Bear (Ursus horribilis) is considered by some biologists as the American race of the circumpolar Brown Bear. However, some scientists consider it a full species. The Grizzly was originally found widely in western North America as far south as Mexico. Now it is found only in a few national parks and other isolated areas in northern United States although it is still fairly common in parts of Canada and Alaska.
Grizzly Bears are up to seven feet long and can weigh up to 850 pounds. Grizzly Bears prefer high mountain areas. They eat a variety of foods including berries, fish, and even small rodents. They will catch salmon during its spawning runs.
Great debates evolved as to whether the bears in Yellowstone Park should be permitted to eat garbage. One argument was that this was an unnatural way of life and it should be discontinued. The other argument was that garbage eating permitted a large bear population with great genetic diversity.
Bear group (Family Ursidae) is found primarily in the Northern Hemisphere. (The Spectacled Bear is found from in Venezuela to Bolivia in the Andes. There are several species found in tropical Malaysia.) There are eight species in this family.
Following is a partial list of some species:
SPECIES LOCATION
Helarctos malayananus Burma, Sumatra, Borneo
(Malayan Sun Bear)
Melursus ursinus India, Sri Lanka
(Sloth Bear)
Selenarctos thibetanus China, Japan, Korea
(Asian Black Bear)
Thalarctos maritimus Arctic Regions
(Polar Bear)
Tremarctos ornatus Andes (Venezuela to Bolivia)
(Ucumari-Spectacled)
Ursus americanus Central Mexico to Alaska
(American Black Bear)
Ursus arctos arctos Europe
(European Brown Bear)
Ursus arctos horribilis North America
(Grizzly Bear)
Ursus arctos middendorfi Kodiak Island
(Big Brown Bear)
Ursus spelaeus Extinct
(Europe Cave Bear)
Carnivores (Order Carnivora) are found naturally worldwide, except for Australia which has an introduced wild dog. Carnivores are characterized by their habits of feeding on other animals. They usually can run quickly and capture their food with the help of their claws and jaws. Typical carnivores are dogs, cats, and bears.
Mammals (Class Mammalia), together with the birds, are among the youngest of the classes of animals. In species count, mammals number about fifty-one hundred, trailing reptiles (approximately fifty-five hundred), fish (approximately eighteen thousand), and birds (approximately eighty-six hundred).
There are three sub-types of mammals:
monotremes, the most primitive:
Develop in reptilian-like eggs and suckle milk emerging
(i.e., spiny anteater, duckbilled platypus)
marsupials
Newborn emerges very underdeveloped and continue to
mature in a pouch on its mother's abdomen (i.e., opossums,
koala, kangaroo)
placental
Embryo develops within the uterus of the female and is
dependent on a placenta for nutrition and waste removal
(i.e., humans, lions, monkeys)
About sixty-five million years ago, the Tertiary era produced thirty-five orders of mammals. Of this number, eighteen have survived to represent Earth's most diversified as well as its most highly developed classification of animals.
Extinction of mammals is fast becoming a serious issue. Duff and Lawson present a list of forty-one extinct species that reached extinction prior to 1800. These forty-one species are not acknowledged in the counts of the various families. Duff and Lawson also present a list of forty-six species including three gazelles, one zebra, one seal, one deer, and one wolf that have probably gone extinct since 1800. These forty-six species are included in the family counts. Science is adding about forty to fifty new species a year to the list. Many of these are the result of divisions of prior species; some are recent discoveries.
Mammals owe their survival to adaptive capabilities that include the ability to exploit whatever sources of food are available to them, as well as their ability to adjust to various climes. Food specialization influenced evolution to such a great extent that the teeth structure can and has been used to provide extensive information on the food needs and various lifestyles of extinct species.
Despite the vast diversity among mammals in terms of size, habitats and adaptations, they share without exception many characteristics such as:
a. body hair
b. mammary glands
c. certain skull characteristics
d. four limbs that permit speed
e. parallel not perpendicular limbs
f. compartmentalized internal organs
g. a four-chambered heart and pulmonary circulation
Backboned Animals (Phylum Chordata) are the most advanced group of animals on earth. These animals are characterized by having a spinal cord or backbone. Most members have a clearly defined brain that controls the organism through a spinal cord. Fish, amphibians, reptiles, birds, and mammals are in this phylum.
Currently, some taxonomists believe that the fish should be divided into two groups (sharks and regular fishes) and that there are some other primitive groups in the phylum such as hagfish or lampreys.
Animal Kingdom contains numerous organisms that feed on other animals or plants. Included in the animal kingdom are the lower marine invertebrates such as sponges and corals, the jointed legged animals such as insects and spiders, and the backboned animals such as fish, amphibians, reptiles, birds, and mammals.