Bears are carnivoran mammals of the family Ursidae. They are classified as caniforms, or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats throughout most of the Northern Hemisphere and partially in the Southern Hemisphere. Bears are found on the continents of North America, South America, and Eurasia. Common characteristics of modern bears include large bodies with stocky legs, long snouts, small rounded ears, shaggy hair, plantigrade paws with five nonretractile claws, and short tails.
The brown bear is a large bear native to Eurasia and North America. Of the carnivorans, it is rivaled in size only by its closest relative, the polar bear, which is much less variable in size and slightly bigger on average. The brown bear is a sexually dimorphic species, as adult males are larger and more compactly built than females. The fur ranges in color from cream to reddish to dark brown. It has evolved large hump muscles, unique among bears, and paws up to 21 cm (8.3 in) wide and 36 cm (14 in) long, to effectively dig through dirt. Its teeth are similar to those of other bears and reflect its dietary plasticity.
The American black bear, or simply black bear, is a species of medium-sized bear endemic to North America. It is the continent's smallest and most widely distributed bear species. It is an omnivore, with a diet varying greatly depending on season and location. It typically lives in largely forested areas but will leave forests in search of food and is sometimes attracted to human communities due to the immediate availability of food.
Hibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It is most commonly used to pass through winter months – called overwintering.
The groundhog, also known as the woodchuck, is a rodent of the family Sciuridae, belonging to the group of large ground squirrels known as marmots. A lowland creature of North America, it is found through much of the Eastern United States, across Canada and into Alaska. It was given its scientific name as Mus monax by Carl Linnaeus in 1758, based on a description of the animal by George Edwards, published in 1743.
Eating is the ingestion of food. In biology, this is typically done to provide a heterotrophic organism with energy and nutrients and to allow for growth. Animals and other heterotrophs must eat in order to survive — carnivores eat other animals, herbivores eat plants, omnivores consume a mixture of both plant and animal matter, and detritivores eat detritus. Fungi digest organic matter outside their bodies as opposed to animals that digest their food inside their bodies.
The mallard or wild duck is a dabbling duck that breeds throughout the temperate and subtropical Americas, Eurasia, and North Africa. It has been introduced to New Zealand, Australia, Peru, Brazil, Uruguay, Argentina, Chile, Colombia, the Falkland Islands, and South Africa. Belonging to the subfamily Anatinae of the waterfowl family Anatidae, mallards live in wetlands, eat water plants and small animals, and are social animals preferring to congregate in groups or flocks of varying sizes.
The Kodiak bear, also known as the Kodiak brown bear and sometimes the Alaskan brown bear, inhabits the islands of the Kodiak Archipelago in southwest Alaska. It is one of the largest recognized subspecies or population of the brown bear, and one of the two largest bears alive today, the other being the polar bear. They are also considered by some to be a population of grizzly bears.
The Eurasian brown bear is one of the most common subspecies of the brown bear, and is found in much of Eurasia. It is also called the European brown bear, common brown bear, common bear, and colloquially by many other names. The genetic diversity of present-day brown bears has been extensively studied over the years and appears to be geographically structured into five main clades based upon analysis of the mtDNA.
The Syrian brown bear is a medium-sized and endangered subspecies of Eurasian brown bear native to the Middle East and West-Central Asia, particularly around the Caucasus Mountains.
The Himalayan brown bear, also known as the Himalayan red bear or isabelline bear, is a subspecies of the brown bear occurring in the western Himalayas. It is the largest mammal in the region, males reaching up to 2.2 m long, while females are a little smaller. It is omnivorous and hibernates in dens during the winter.
Osteophagy is the practice in which animals, usually herbivores, consume bones. Most vegetation around the world lacks sufficient amounts of phosphate. Phosphorus is an essential mineral for all animals, as it plays a major role in the formation of the skeletal system, and is necessary for many biological processes including: energy metabolism, protein synthesis, cell signaling, and lactation. Phosphate deficiencies can cause physiological side effects, especially pertaining to the reproductive system, as well as side effects of delayed growth and failure to regenerate new bone. The importance of having sufficient amounts of phosphorus further resides in the physiological importance of maintaining a proper phosphorus to calcium ratio. Having a Ca:P ratio of 2:1 is important for the absorption of these minerals, as deviations from this optimal ratio can inhibit their absorption. Dietary calcium and phosphorus ratio, along with vitamin D, regulates bone mineralization and turnover by affecting calcium and phosphorus transport and absorption in the intestine.
The Gobi bear, known in Mongolian as the Mazaalai (Мазаалай), is a subspecies of the brown bear that is found in the Gobi Desert of Mongolia. It is listed as critically endangered by the Mongolian Redbook of Endangered Species and by IUCN standards. Currently, there are only 31 bears left in the Mongolian Gobi Desert; through long-term genetic monitoring it is known that the population is relatively stable, however, the sex ratio is highly skewed towards males. Gobi bears are separated by enough distance from other brown bear populations to achieve reproductive isolation. In 1959, hunting of the animal was prohibited in order to preserve the dying subspecies.
The Kamchatka brown bear, also known as the Far Eastern brown bear, or in Russian: камчатский бурый медведь, romanized: kamchatsky bury medved, is a subspecies of brown bear native to the Russian Kamchatka Peninsula.
The Marsican brown bear, also known as the Apennine brown bear, and orso bruno marsicano in Italian, is a critically endangered population of the Eurasian brown bear, with a range restricted to the Parco Nazionale d'Abruzzo, Lazio e Molise, and the surrounding region in Italy. The Marsican brown bear differs slightly from other brown bears in its appearance and hibernation techniques. The bear's popular name is derived from Marsica, a historic area of the modern-day region of Abruzzo where the bear has long had a significant presence.
The Cantabrian brown bear, Iberian brown bear, or Iberian bear is a population of Eurasian brown bears living in the Cantabrian Mountains of Spain.
Oleoylethanolamide (OEA) is an endogenous peroxisome proliferator-activated receptor alpha (PPAR-α) agonist. It is a naturally occurring ethanolamide lipid that regulates feeding and body weight in vertebrates ranging from mice to pythons.
The grizzly bear, also known as the North American brown bear or simply grizzly, is a population or subspecies of the brown bear inhabiting North America.
Formerly or currently considered subspecies or populations of brown bears have been listed as follows:
The brown bear is one of the most omnivorous animals in the world and has been recorded to consume the greatest variety of foods of any bear. Throughout life, this species is regularly curious about the potential of eating virtually any organism or object that they encounter. Certainly no other animal in their given ecosystems, short perhaps of other bear species and humans, can claim to feed on as broad a range of dietary opportunities. Food that is both abundant and easily obtained is preferred. Their jaw structure has evolved to fit their dietary habits. Their diet varies enormously throughout their differing areas based on opportunity. In spring, winter-provided carrion, grasses, shoots, sedges and forbs are the dietary mainstays for brown bears from almost every part of their distribution. Fruits, including berries, become increasingly important during summer and early autumn. Roots and bulbs become critical in autumn for some inland bear populations if fruit crops are poor. The dietary variability is illustrated in the western United States, as meat made up 51% of the average year-around diet for grizzly bears from Yellowstone National Park, while it made up only 11% of the year-around diet for grizzlies from Glacier National Park a few hundred miles to the north.
