|
||||||||||||||||||||||||||||||||
|

American Black BearThe American Black Bear (''Ursus americanus''), also known as simply the black bear or cinnamon bear, is the most common bear in North America. The black bear occurs throughout much of North America from northern Canada and Alaska south into Mexico and from the Atlantic Ocean to the Pacific Ocean. This includes 39 of the 50 U.S. states and all Canadian provinces. Populations in east-central and the southern United States remain in the protected mountains and woodlands of parks and preserves. While there were probably once as many as two million black bears in North America, the population declined to a low of 200,000 before rebounding in recent decades, partly due to conservation measures. By current estimates, more than 600,000 are living today.[http://biology.usgs.gov/s+t/noframe/c286.htm] == Appearance == The black bear is about 1.5 metres (5 feet) long. Females weigh between 40 and 180 kg (90 and 400 pounds), while males weigh between 50 and 400 kg (110 and 880 pounds). Cubs usually weigh between 200 and 450 g (between 7 oz and 1 pound) at birth. The adult black bear has small eyes, rounded ears, a long snout, a large body, and a short tail. Though these bears indeed generally have shaggy black hair, the coat can vary in color depending on the subspecies: from white through chocolate brown, cinnamon brown, and blonde, found mostly West of the Mississippi River, to black in the East. Further adding to the confusion, black bears occasionally sport a slight white chest blaze on either side of the river. While black bears are able to stand and walk on their hind legs, the usually stand or walk on all four legs. The black bear's characteristic shuffle results from walking flat-footed, with the hind legs slightly longer than the front legs. Each paw has five strong claws used for tearing, digging, and climbing. One blow from a powerful front paw is enough to kill an adult deer. == Habitat and behavior == Black bears prefer forested and shrubby areas but use wet meadows, high tidelands, ridgetops, burned areas, riparian areas, and avalanche chutes. They also frequent swampy hardwood and conifer forests. After emerging from their winter dens in spring, they seek southerly slopes at lower elevations for forage and move to northerly and easterly slopes at higher elevations as summer progresses. Black bears use dense cover for hiding and thermal protection, as well as for bedding. They climb trees to escape danger and use forested areas as travel corriders. Black bears hibernate during winter and may build dens in tree cavities, under logs, rocks, in banks, caves, or culverts, and in shallow depressions. Black bears reach breeding maturity at about 4 or 5 years of age, and breed every 2 to 3 years. Black bears breed in the spring, usually in May and June, but the embryos do not begin to develop until the mother dens in the fall to hibernate through the winter months. However, if food was scarce and the mother has not gained enough fat to sustain herself during hibernation as well as produce cubs, the embryos do not implant (develop). Black bear cubs are generally born in January or February. They are blind when born, and twins are most common, though first-time mothers typically only have a single cub. By spring thaw, when the bears start leaving their dens, the cubs are fur-balls of energy, inquisitive and playful. They are weaned between July and September of their first year, and stay with the mother through the first full winter. They are usually independent by the second winter. Cub survival is totally dependent on the skill of the mother in teaching her cubs what to eat, where and how to forage (find food), where to den, and when and where to seek shelter from heat or danger. Black bears eat a wide variey of foods, relying most heavily on grasses, herbs, fruits, and mast. They also feed on carrion and insects such as * carpenter ants ''(Campanotus spp.)'' * yellow jackets (''Vespula spp.'') * bees (Apidae) * termites (Isoptera). Black bears sometimes kill and eat small rodents and ungulate fawns. Black bears eat a great variety of vegetation and nuts as shown in the list below. It is notable that the list reflects the different types of habitat in which the black bear is found: *oak (''Quercus spp.'') mast *hazel (''Corylus spp.'') mast *mountain ash (''Sorbus spp.'') *tree cambium *dogwood (''Cornus spp.'') *manzanita *kinnikinnick (''Arctostaphylos spp.'') *cranberry (''Vibernum spp.'') *blueberry *huckleberry (''Vaccinium spp.'') *raspberry *blackberry (''Rubus spp.'') *rose hips (''Rosa spp.'') *gooseberry (''Ribes spp.'') *sarsaparilla (''Aralia nudicaulis'') *rhubarb (''Polygonum alaskanum'') *lupine (''Lupinus spp.'') *northern bedstraw (''Galium boreale'') *lousewort (''Pedicularis spp.'') *Labrador tea (''Ledum groenlandicus'') *California coffeeberry (''Rhamnus californicus'') *squawroot (''Conopholis americana'') *dandelion (''Taraxacum officinale'') *clover (''Trifolium spp.'') *thistle (''Cirsium spp.'') * black walnut (''Juglans nigra'') *buffaloberry (''Shepherdia canadensis'') *lomatium (''Lomatium spp.'') *cowparsnip (''Heracleum lanatum'') *pine nuts. *chestnuts (''castanea dentata'') * wild grapes (''vitis riparia'') * wild strawberries (''fragaria virginiana'') Black bears also eat salmon (''Oncorynchus spp.'', ''salmo salar'') and raid orchards, beehive (beekeeping), and crop fields. They pick from garbage dumps and trash bins of private homes. Black bears may occasionally prey on domestic sheep and pigs when their natural foods are scarce. Black bear predators include human, the grizzly (''Ursus arctos horriblis''), and other Black bears. Coyotes (''Canis latrans'') and mountain lions (''puma concolor'') may prey on cubs. == History and Controversy == Because their behavior has been little understood until recently, black bears have been feared and hated. Before the 20th century these bears were shot intermittently as vermin, food, and trophies being seen as either a vicious beast or an endless commodity; The British beefeater's hat is made of black bear fur shipped from Canada as has been for many years and black bear rugs are not unknown in antique shops. Paradoxically, they have also been portrayed as harmless and cuddly. For example, the "teddy bear" owes its existence to a young black bear cub Theodore Roosevelt refused to shoot. To date, black bears are as much an important game species as they are a point of debate across the continent, especially when it comes to the fact that many are finding life in the suburbs quite comfortable. Their tendencies to follow their stomachs and habitat encroachment by man have created man-bear conflicts. This is true especially in areas where they may have been uncommon or absent for a long time, as in many parts of the eastern United States. An excellent example is the state of New Jersey. In New Jersey, bears were quite uncommon before the modern era as much land was cleared for homes and farming and also due to poor policies regarding hunting and forestry; by 1970 there were only 100 bears extant. However, due to changes in land usage, management, and population increases in neighboring Pennsylvania and New York, that number increased to nearly 1500 bears by 2003. The result is that the residents of this most densely populous state sometimes awaken to find the garbage ripped to shreds or a birdfeeder knocked to the ground at best, and at worst a bear invading the home or attacking. (Invasion usually happens after a bear has lost its fear and come to associate people with food and attacks occur when a human gets in the way of said food.) This is a cause for concern among civilians and scientists alike. == Taxonomy and subspecies ranges == The American black bear is classified as being in the class Mammalia, order Carnivora and family Ursidae. Currently accepted subspecies (with their respective ranges) include:
American Black BearThere was a conflict of data within the page about the weight of new born cubs. I have resolved it from Animal Diversity Web, which is usually reliable on such matters. User:Seglea 21:12, 2 May 2005 (UTC) Sorry if this is the wrong place, but "Females typically weight about 40 kg" this doesn't sound right to me. :yes, it does sound a bit low, but it agrees with data from the US Fish and Wildlife service page in the External Links list User:Seglea 18:18, 5 May 2005 (UTC) ::I just looked there, and it says "from 125 to 400" pounds, not specifically mentioning females. 40 kg would be about 85 pounds only. The us forest service external link says "females between 150 and 400 pounds". The bear center external link says: "Wild females usually weigh between 90 and 300 pounds". So, none of the three external links is anywhere near saying "Females typically weigh about 40 kg", note the "typical" in there - it's not the minimum. My suspicion is, the number was doubly converted from pounds, so 200 pounds (which seems to be a typical weight for femals, from all 3 external links) -> 90 kg and then wrongly 90 pounds -> 40kg. 15 May 2005 :::Looked also on Animal Diversity Web, which says females weigh between 39 and 236 kg, and males between 47 and 409 kg, so modified the page accordingly. American black bear#REDIRECT American_Black_Bear See other meanings of words starting from letter: AAB | AC | AD | AE | AF | AG | AH | AI | AJ | AK | AL | AM | AN | AO | AP | AR | AS | AT | AU | AW | AX | AY | AZ |Words begining with American_Black_Bear: American_Black_Bear American_Black_Bear American_black_bear
Sponsored links: praca.
|
||||||||||||||||||||||||||||||||
These materials are based on Wikipedia and licensed under the GNU FDL
YouTube.com videos better site than Turbo Tax 2007 | ||||||||||||||||||||||||||||||||
|
|