family of mammals
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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-eyed variety of habitats throughout the Northern Hemisphere and partially in the Southern Hemisphere. Bears are found on the continents of North America, South America, Europe, and Asia. Common characteristics of modern bears include large bodies with compact legs, hanker snouts, small rounded ears, bushy haircloth, plantigrade paw with five nonretractile claw, and short tails. While the diametric bear is largely carnivorous, and the giant giant panda feeds about entirely on bamboo, the remaining six species are omnivorous with change diets. With the exception of courting individuals and mothers with their young, bears are typically lone animals. They may be diurnal or nocturnal and have an excellent smell of smell. Despite their fleshy build and awkward gait, they are adept runners, climbers, and swimmers. Bears consumption shelters, such as caves and logs, as their dens ; most species occupy their dens during the winter for a hanker period of hibernation, up to 100 days. Bears have been hunted since prehistoric times for their kernel and fur ; they have been used for bear-baiting and other forms of entertainment, such as being made to dance. With their brawny physical presence, they play a big role in the arts, mythology, and early cultural aspects of diverse homo societies. In mod times, bears have come under pressure through invasion on their habitats and illegal trade in have a bun in the oven parts, including the asian bile bear market. The IUCN lists six have a bun in the oven species as vulnerable or endangered, and tied least concern species, such as the brown bear, are at gamble of ablation in certain countries. The poach and international trade of these most endanger populations are prohibited, but still ongoing .
etymology
The English bible “ bear ” comes from Old English bera and belongs to a family of names for the bear in Germanic languages, such as swedish björn, besides used as a first name. This class is conventionally said to be related to a Proto-Indo-European news for “ embrown ”, so that “ bear ” would mean “ the brown one ”. [ 1 ] [ 2 ] however, Ringe notes that while this etymology is semantically plausible, a word entail “ brown university ” of this form can not be found in Proto-Indo-European. He suggests alternatively that “ yield ” is from the Proto-Indo-European news *ǵʰwḗr- ~ *ǵʰwér “ fantastic animal ”. [ 3 ] This terminology for the animal originated as a forbidden avoidance term : proto-Germanic tribes replaced their original password for bear— arkto —with this euphemistic expression out of fear that speaking the animal ‘s truthful list might cause it to appear. [ 4 ] [ 5 ] According to generator Ralph Keyes, this is the oldest know euphemism. [ 6 ] Bear taxonomic group names such as Arctoidea and Helarctos come from the ancient greek ἄρκτος ( arktos ), meaning bear, [ 7 ] as do the names “ arctic “ and “ antarctic “, via the name of the configuration Ursa Major, the “ great Bear ”, outstanding in the northern flip. [ 8 ] Bear taxonomic group names such as Ursidae and Ursus come from Latin Ursus/Ursa, he-bear/she-bear. [ 8 ] The female first name “ Ursula “, in the first place derived from a christian saint ‘s name, means “ little she-bear ” ( diminutive of Latin ursa ). In Switzerland, the male beginning name “ Urs ” is specially popular, while the name of the canton and city of Bern is derived from Bär, german for bear. The Germanic name Bernard ( including Bernhardt and similar forms ) means “ bear-brave ”, “ bear-hardy ”, or “ bold bear ”. [ 9 ] [ 10 ] The Old English mention Beowulf is a kenning, “ bee-wolf ”, for bear, in turn meaning a weather warrior. [ 11 ]
taxonomy
The family Ursidae is one of nine families in the suborder Caniformia, or “ doglike ” carnivorans, within the regulate Carnivora. Bears ‘ closest living relatives are the pinnipeds, canids, and musteloids. [ 12 ] Modern bears comprise eight species in three subfamilies : Ailuropodinae ( monotypic with the colossus giant panda ), Tremarctinae ( monotypic with the bespectacled hold ), and Ursinae ( containing six species divided into one to three genus, depending on the authority ). nuclear chromosome analysis show that the karyotype of the six ursine bears is closely identical, each having 74 chromosomes ( see Ursid hybrid ), whereas the giant giant panda has 42 chromosomes and the spectacled yield 52. These smaller numbers can be explained by the fuse of some chromosomes, and the ring patterns on these match those of the ursine species, but differ from those of procyonids, which supports the inclusion body of these two species in Ursidae quite than in Procyonidae, where they had been placed by some earlier authorities. [ 13 ]
evolution
Plithocyon armagnacensis skull, a member of the extinct subfamily Hemicyoninae from the skull, a extremity of the extinct subfamily Hemicyoninae from the Miocene The earliest members of Ursidae belong to to the extinct subfamily Amphicynodontinae, including Parictis ( late Eocene to early in-between Miocene, 38–18 Mya ) and the slenderly younger Allocyon ( early Oligocene, 34–30 Mya ), both from North America. These animals looked very different from today ‘s bears, being small and raccoon -like in overall appearance, with diets possibly more alike to that of a badger. Parictis does not appear in Eurasia and Africa until the Miocene. [ 14 ] It is ill-defined whether late-Eocene ursids were besides stage in Eurasia, although faunal exchange across the Bering domain bridge may have been potential during a major ocean degree low stand vitamin a early as the late Eocene ( about 37 Mya ) and continuing into the early Oligocene. [ 15 ] european genus morphologically identical similar to Allocyon, and to the much younger american Kolponomos ( about 18 Mya ), [ 16 ] are known from the Oligocene, including Amphicticeps and Amphicynodon. [ 15 ] There has been versatile morphologic testify linking amphicynodontines with pinnipeds, as both groups were semi-aquatic, otter-like mammals. [ 17 ] [ 18 ] [ 19 ] In addition to the back of the pinniped–amphicynodontine clade, other morphologic and some molecular evidence supports bears being the closest living relatives to pinnipeds. [ 20 ] [ 21 ] [ 22 ] [ 18 ] [ 23 ] [ 19 ]
Arctotherium bonariense Life restoration of The raccoon-sized, dog-like Cephalogale is the oldest-known extremity of the subfamily Hemicyoninae, which first appeared during the middle Oligocene in Eurasia about 30 Mya. [ 15 ] The subfamily includes the younger genus Phoberocyon ( 20–15 Mya ), and Plithocyon ( 15–7 Mya ). A Cephalogale -like species gave get up to the genus Ursavus during the early Oligocene ( 30–28 Mya ) ; this genus proliferated into many species in Asia and is ancestral to all survive bears. Species of Ursavus subsequently entered North America, together with Amphicynodon and Cephalogale, during the early Miocene ( 21–18 Mya ). Members of the be lineages of bears diverged from Ursavus between 15 and 20 Mya, [ 24 ] [ 25 ] likely via the species Ursavus elmensis. Based on genetic and morphologic data, the Ailuropodinae ( lesser panda ) were the first base to diverge from other living bears about 19 Mya, although no fossils of this group have been found before about 5 Mya. [ 26 ] The New World short-faced bears ( Tremarctinae ) differentiated from Ursinae following a dispersion consequence into North America during the mid-Miocene ( about 13 Mya ). [ 26 ] They invaded South America ( ≈2.5 or 1.2 Ma ) following constitution of the Isthmus of Panama. [ 27 ] Their earliest fossil representative is Plionarctos in North America ( c. 10–2 Ma ). This genus is probably the calculate ancestor to the north american english short-faced bears ( genus Arctodus ), the south american short-faced bears ( Arctotherium ), and the bespectacled bears, Tremarctos, represented by both an extinct north american species ( T. floridanus ), and the lone surviving spokesperson of the Tremarctinae, the south american english spectacled bear ( T. ornatus ). [ 15 ]
Ursus spelaeus), a relative of the brown bear and polar bear from the Fossil of the cave behave ), a relative of the embrown bear and polar digest from the Pleistocene epoch in Europe The subfamily Ursinae experienced a dramatic proliferation of taxonomic group about 5.3–4.5 Mya, coincident with major environmental changes ; the first members of the genus Ursus appeared around this time. [ 26 ] The sloth bear is a modern survivor of one of the earliest lineages to diverge during this radiation event ( 5.3 Mya ) ; it took on its curious morphology, related to its diet of termites and ants, no late than by the early Pleistocene. By 3–4 Mya, the species Ursus minimus appears in the fossil record of Europe ; aside from its size, it was about identical to today ‘s asian black bear. It is probable ancestral to all bears within Ursinae, possibly away from the sloth bear. Two lineages evolved from U. minimus : the total darkness bears ( including the sunlight bear, the asian blacken digest, and the american black give birth ) ; and the brown bears ( which includes the pivotal bear ). Modern brown bears evolved from U. minimus via Ursus etruscus, which itself is ancestral to the extinct Pleistocene cave bear. Species of Ursinae have migrated repeatedly into North America from Eurasia arsenic early as 4 Mya during the early Pliocene. [ 28 ] [ 29 ] The polar hold is the most recently evolved species and descended from a population of brown bears that became isolated in northerly latitudes by glaciation 400,000 years ago. [ 30 ]
evolution
The bears form a clade within the Carnivora. The cladogram is based on molecular evolution of six genes in Flynn, 2005. [ 31 ]
note that although they are called “ bears ” in some languages, red giant panda and raccoons and their conclude relatives are not bears, but quite musteloids. [ 31 ] There are two phylogenetic hypotheses on the relationships among extant and dodo give birth species. One is all species of bears are classified in seven subfamilies as adopted hera and associate articles : Amphicynodontinae, Hemicyoninae, Ursavinae, Agriotheriinae, Ailuropodinae, Tremarctinae, and Ursinae. [ 32 ] [ 33 ] [ 34 ] [ 35 ] Below is a cladogram of the subfamilies of bears after McLellan and Reiner ( 1992 ) [ 32 ] and Qiu et al. ( 2014 ) : [ 35 ]
The second option phylogenetic guess was implemented by McKenna et aluminum. ( 1997 ) to classify all the bear species into the superfamily Ursoidea, with Hemicyoninae and Agriotheriinae being classified in the class “ Hemicyonidae ”. [ 36 ] Amphicynodontinae under this classification were classified as stem- pinnipeds in the superfamily Phocoidea. [ 36 ] In the McKenna and Bell classification both bears and pinnipeds are in a parvorder of carnivoran mammals known as Ursida, along with the extinct give birth dogs of the family Amphicyonidae. [ 36 ] Below is the cladogram based on McKenna and Bell ( 1997 ) categorization : [ 36 ]
The evolution of extant bear species is shown in a cladogram based on complete mitochondrial deoxyribonucleic acid sequences from Yu et al. ( 2007 ) [ 37 ] The giant lesser panda, followed by the bespectacled digest, are distinctly the oldest species. The relationships of the other species are not very well resolved, though the polar behave and the brown bear form a close up group. [ 13 ]
physical characteristics
size
polar wear ( left ) and sun hold, the largest and smallest species respectively, on average The wear class includes the most massive extant tellurian members of the order Carnivora. [ a ] The pivotal bear is considered to be the largest extant species, [ 39 ] with adult males weighing 350–700 kilograms ( 770–1,500 pounds ) and measuring 2.4–3 metres ( 7 foot 10 in–9 foot 10 in ) in entire length. [ 40 ] The smallest species is the sun give birth, which ranges 25–65 kilogram ( 55–145 pound ) in weight and 100–140 curium ( 40–55 in ) in distance. [ 41 ] Prehistoric North and South american short-faced bears were the largest species known to have lived. The latter estimated to have weighed 1,600 kg ( 3,500 pound ) and stood 3.4 thousand ( 11 foot 2 in ) tall. [ 42 ] [ 43 ] Body weight varies throughout the class in bears of temperate and arctic climates, as they build up adipose tissue reserves in the summer and fall and lose weight during the winter. [ 44 ]
morphology
Bears are by and large bulky and robust animals with curtly tails. They are sexually dimorphic with respect to size, with males typically being larger. [ 45 ] [ 46 ] Larger species tend to show increase levels of intimate dimorphism in comparison to smaller species. [ 46 ] Relying as they do on strength preferably than amphetamine, bears have relatively short limbs with chummy bones to support their bulge. The shoulder blades and the pelvis are correspondingly massive. The limbs are much straighter than those of the adult cats as there is no necessitate for them to flex in the same way due to the differences in their pace. The potent forelimbs are used to catch raven, to excavate dens, to dig out burrowing animals, to turn over rocks and logs to locate prey, and to club big creatures. [ 44 ]
Despite being quadrupeds, bears can stand and sit as humans do. Unlike most other country carnivorans, bears are plantigrade. They distribute their weight toward the back feet, which makes them look lumbering when they walk. They are able of bursts of amphetamine but soon bore, and as a consequence largely trust on ambush rather than the chase. Bears can stand on their back feet and sit up straight with remarkable balance. Their front paws are flexible adequate to grasp yield and leaves. Bears ‘ non-retractable claws are used for dig, climbing, tearing, and catching prey. The hook on the front feet are larger than those on the back and may be a hindrance when climbing trees ; black bears are the most arborical of the bears, and have the shortest claw. Pandas are unique in having a bony propagation on the wrist of the front feet which acts as a ovolo, and is used for gripping bamboo shoots as the animals feed. [ 44 ] Most mammals have agouti hair, with each individual hair shaft having bands of color corresponding to two different types of melanin pigment. Bears however have a single type of melanin and the hairs have a single color throughout their length, apart from the tip off which is sometimes a different shade. The coat consists of long guard hair, which form a protective bushy cover, and brusque dense hairs which form an isolate layer trapping atmosphere close to the hide. The shagged coat helps maintain body heat during winter hibernation and is shed in the bounce leaving a shorter summer coat. polar bears have hollow, translucent guard hairs which gain heat from the sun and behavior it to the dark-colored bark below. They have a thick layer of blubber for extra insulation, and the soles of their feet have a dense pad of fur. [ 44 ] While bears tend to be uniform in coloring material, some species may have markings on the chest of drawers or confront and the giant giant panda has a bold black-and-white coat. [ 47 ] Bears have modest round ears so as to minimize heat loss, but neither their learn or sight are particularly acute. Unlike many early carnivorans they have color vision, possibly to help them distinguish advanced nuts and fruits. They are unique among carnivorans in not having touch-sensitive whiskers on the gun muzzle ; however, they have an excellent sense of smell, better than that of the chase, or possibly any other mammal. They use smell for signalling to each other ( either to warn off rivals or detect mates ) and for finding food. Smell is the principal sense used by bears to locate most of their food, and they have excellent memories which helps them to relocate places where they have found food before. [ 44 ]
Brown bear skull The skulls of bears are massive, put up anchorage for the herculean masseter and temporal role jaw muscles. The canine tooth are big but largely used for display, and the molar teeth flat and crushing. Unlike most other members of the Carnivora, bears have relatively unexploited carnassial tooth, and their teeth are adapted for a diet that includes a significant amount of vegetable count. [ 44 ] considerable variation occurs in dental rule even within a given species. This may indicate bears are distillery in the process of evolving from a chiefly flesh-eating diet to a predominantly herbivorous one. polar bears appear to have secondarily re-evolved carnassial-like boldness tooth, as their diets have switched back towards carnivory. [ 48 ] Sloth bears lack lower central incisors and use their protusible lips for sucking up the termites on which they feed. [ 44 ] The general dental formula for living bears is : 3.1.2–4.23.1.2–4.3. [ 44 ] The structure of the larynx of bears appears to be the most radical of the caniforms. [ 49 ] They possess air pouches connected to the throat which may amplify their vocalizations. [ 50 ] Bears have a fairly simple digestive system typical for carnivorans, with a single stomach, short undifferentiated intestines and no cecum. [ 51 ] [ 52 ] tied the herbivorous giant giant panda still has the digestive system of a carnivore, angstrom well as carnivore-specific genes. Its ability to digest cellulose is ascribed to the microbes in its catgut. [ 53 ] Bears must spend much of their time feed in order to gain enough nutrition from leaf. The giant panda, in particular, spends 12–15 hours a day eating. [ 54 ]
distribution and habitat
extant bears are found in sixty countries primarily in the Northern Hemisphere and are concentrated in Asia, North America, and Europe. An exception is the bespectacled yield ; native to South America, it inhabits the andean area. [ 55 ] The sunday bear ‘s range extends below the equator in Southeast Asia. [ 56 ] The Atlas bear, a subspecies of the brown behave was distributed in North Africa from Morocco to Libya, but it became extinct around the 1870s. [ 57 ] The most widespread species is the brown behave, which occurs from Western Europe eastwards through Asia to the western areas of North America. The american black bear is restricted to North America, and the polar bear is restricted to the Arctic Sea. All the remaining species of bear are asian. [ 55 ] They occur in a range of habitats which include tropical lowland rain forest, both coniferous and broadleaf forests, prairies, steppes, montane grassland, alpine talus slopes, Arctic tundra and in the case of the diametric digest, ice floes. [ 55 ] [ 58 ] Bears may dig their dens in hillsides or use caves, empty logs and dense vegetation for shelter. [ 58 ]
Behavior and ecology
Brown and American black bears are by and large diurnal, meaning that they are active voice for the most part during the day, though they may forage substantially by night. [ 59 ] other species may be nocturnal, active at night, though female sloth bears with cubs may feed more at day to avoid competition from conspecifics and nocturnal predators. [ 60 ] Bears are overwhelmingly lonely and are considered to be the most asocial of all the Carnivora. The only times bears are encountered in groups are mothers with young or periodic seasonal worker bounties of full-bodied food ( such as salmon runs ). [ 61 ] [ 62 ] Fights between males can occur and older individuals may have across-the-board scar, which suggests that maintaining authority can be intense. [ 63 ] With their acute accent sense of smack, bears can locate carcasses from several kilometres away. They use smell to locate other foods, meet mates, keep off rivals and recognize their cub. [ 44 ]
Feeding
Most bears are opportunist omnivores and consume more plant than animal matter. They eat anything from leaves, roots, and berries to insects, carrion, fresh kernel, and fish, and have digestive systems and teeth adapted to such a diet. [ 55 ] At the extremes are the about wholly herbivorous giant giant panda and the largely carnivorous arctic bear. however, all bears feed on any food beginning that becomes seasonally available. [ 54 ] For exemplar, Asiatic black bears in Taiwan consume bombastic numbers of acorns when these are most common, and switch to ungulates at early times of the year. [ 64 ] When foraging for plants, bears choose to eat them at the stage when they are at their most alimentary and digestible, typically avoiding older grasses, sedges and leaves. [ 52 ] [ 54 ] Hence, in more northern temperate areas, browse and graze is more coarse early in jump and late becomes more restrict. [ 65 ] Knowing when plants are ripe for eat is a learn behavior. [ 54 ] Berries may be foraged in bushes or at the tops of trees, and bears try to maximize the numeral of berries consumed versus leaf. [ 65 ] In fall, some digest species forage boastfully amounts of naturally fermented fruits, which affects their behavior. [ 66 ] Smaller bears climb trees to obtain mast ( comestible generative parts, such as acorns ). [ 67 ] such masts can be very significant to the diets of these species, and mast failures may result in long-range movements by bears looking for alternative food sources. [ 68 ] Brown bears, with their powerful jab abilities, normally consume roots. [ 65 ] The lesser panda ‘s diet is over 99 % bamboo, [ 69 ] of 30 unlike species. Its solid jaws are adapted for crushing the tough stem of these plants, though they prefer to eat the more alimentary leaves. [ 70 ] [ 71 ] Bromeliads can make up to 50 % of the diet of the bespectacled bear, which besides has potent jaws to bite them open. [ 72 ]
Brown bear feeding on infrequent, but predictable, pink-orange migrations in Alaska The sloth bear is not a specialized as polar bears and the lesser panda, has lost several front teeth normally seen in bears, and developed a long, suctioning natural language to feed on the ants, termites, and other burrow insects. At certain times of the year, these insects can make up 90 % of their diets. [ 73 ] Some individuals become addicted to sweets in garbage inside towns where tourism-related waste is generated throughout the year. [ 74 ] Some species may raid the nests of wasp and bees for the honey and unfledged insects, in malice of stinging from the adults. [ 75 ] Sun bears use their long tongues to lick up both insects and honey. [ 76 ] Fish are an authoritative reference of food for some species, and embrown bears in particular meet in bombastic numbers at salmon runs. typically, a yield plunges into the water system and seizes a pisces with its jaw or front paw. The choose parts to eat are the brain and eggs. Small burrowing mammals like rodents may be dug out and eaten. [ 77 ] [ 65 ]
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polar digest feeding on a cachet on an ice floe north of Svalbard, Norway. It is the most carnivorous species. The brown bear and both species of black bears sometimes take large ungulates, such as deer and bovids, by and large the young and faint. [ 64 ] [ 78 ] [ 77 ] These animals may be taken by a light rush and ambush, though hiding young may be stiffed out and pounced on. [ 65 ] [ 79 ] The arctic bear chiefly preys on seals, stalking them from the frosting or breaking into their dens. They primarily eat the highly digestible fatness. [ 80 ] [ 77 ] Large mammal prey is typically killed by a pungency to the drumhead or neck, or ( in the case of young ) merely pinned down and mauled. [ 65 ] [ 81 ] Predatory behavior in bears is typically teach to the youthful by the mother. [ 77 ] Bears are prolific scavengers and kleptoparasites, stealing food caches from rodents, and carcasses from other predators. [ 52 ] [ 82 ] For hibernating species, weight acquire is authoritative as it provides nutriment during winter dormancy. A brown bear can eat 41 kilogram ( 90 pound ) of food and gain 2–3 kilogram ( 4–7 pound ) of fat a day prior to entering its lair. [ 83 ]
communication
Bears produce a issue of vocal and non-vocal sounds. Tongue-clicking, grunting or chuffing many be made in cordial situations, such as between mothers and cubs or courting couples, while moaning, huffing, snorting or blowing air travel is made when an person is stressed. Barking is produced during times of alarm, excitation or to give away the animal ‘s position. Warning sounds include jaw-clicking and lip-popping, while teeth-chatters, bellows, growl, roars and pulsing sounds are made in aggressive encounters. Cubs may squeal, bawl, bleat or screech when in distress and make motor-like hum when comfortable or nurse. [ 49 ] [ 84 ] [ 85 ] [ 86 ] [ 87 ] [ 88 ]
Bears sometimes communicate with ocular displays such as standing upright, which exaggerates the individual ‘s size. The chest markings of some species may add to this intimidating display. Staring is an aggressive act and the facial markings of bespectacled bears and elephantine lesser panda may help draw attention to the eyes during agonistic encounters. [ 47 ] Individuals may approach each early by stiff-legged walk with the principal lowered. Dominance between bears is asserted by making a frontal orientation, showing the canine tooth, muzzle twist and neck extend. A hyponym may respond with a lateral predilection, by turning away and dropping the head and by sitting or lying down. [ 62 ] [ 89 ] Bears may mark territory by rubbing against trees and other objects which may serve to spread their scent. This is normally accompanied by clawing and biting the aim. Bark may be spread around to draw attention to the marking stake. [ 90 ] Pandas are known to mark objects with urine and a bendable meaning from their anal glands. [ 91 ] Polar bears leave behind their aroma in their tracks which allow individuals to keep track of one another in the huge Arctic wilderness. [ 92 ]
reproduction and development
The coupling system of bears has variously been described as a phase of polygyny, promiscuity and serial monogamy. [ 93 ] [ 94 ] [ 95 ] During the breed season, males take notice of females in their vicinity and females become more broad of males. A male bear may visit a female endlessly over a period of several days or weeks, depending on the species, to test her generative state. During this time period, males try to prevent rivals from interacting with their match. courtship may be brief, although in some asian species, courting pairs may engage in writhe, caressing, mock fight and articulate. ovulation is induced by felt, which can last up to 30 minutes depending on the species. [ 94 ]
Gestation typically lasts 6–9 months, including delayed implantation, and litter size numbers up to four cub. [ 96 ] Giant lesser panda may give parturition to twins but they can only suckle one young and the other is left to die. [ 97 ] In northern surviving species, give birth takes place during winter quiescence. Cubs are born blind and helpless with at most a dilute level of hair, relying on their mother for heat. The milk of the female bear is full-bodied in fat and antibodies and cubs may suckle for improving to a year after they are born. By 2–3 months, cubs can follow their beget outside the den. They normally follow her on foot, but sloth bear cub may ride on their mother ‘s binding. [ 96 ] [ 58 ] Male bears play no function in raising young. Infanticide, where an adult male kills the cub of another, has been recorded in diametric bears, brown bears and american black bears but not in other species. [ 98 ] Males kill young to bring the female into estrus. [ 99 ] Cubs may flee and the mother defends them even at the cost of her life. [ 100 ] [ 101 ] [ 102 ] In some species, offspring may become mugwump around the adjacent spring, though some may stay until the female successfully mates again. Bears reach sexual maturity concisely after they disperse ; at around 3–6 years depending on the species. Male Alaskan brown bears and diametric bears may continue to grow until they are 11 years old. [ 96 ] Lifespan may besides vary between species. The brown give birth can live an average of 25 years. [ 103 ]
Hibernation
Bears of northern regions, including the american english black bear and the grey bear, hibernate in the winter. [ 104 ] [ 105 ] During hibernation, the hold ‘s metamorphosis slows down, its torso temperature decreases slightly, and its heart rate slows from a normal value of 55 to equitable 9 beats per hour. [ 106 ] Bears normally do not wake during their hibernation, and can go the entire time period without corrode, drink, urinate, or defecating. [ 44 ] A faecal plug is formed in the colon, and is expelled when the hold wakes in the give. [ 107 ] If they have stored adequate body fatten, their muscles remain in good condition, and their protein alimony requirements are met from recycling waste urea. [ 44 ] Female bears give give birth during the hibernation period, and are roused when doing so. [ 105 ]
mortality
Hunters with shot have a bun in the oven, Sweden, early twentieth century. This photograph is in the Nordic Museum Bears do not have many predators. The most important are humans, and as they started cultivating crops, they increasingly came in conflict with the bears that raided them. Since the invention of firearms, people have been able to kill bears with greater ease. [ 108 ] Felids like the tiger may besides prey on bears, [ 109 ] [ 110 ] particularly cubs, which may besides be threatened by canids. [ 13 ] [ 95 ] Bears are parasitized by eighty species of parasites, including single-celled protozoans and gastro-intestinal worms, and nematodes and flukes in their heart, liver, lungs and bloodstream. outwardly they have ticks, fleas and louse. A study of american black bears found seventeen species of endoparasite including the protozoal Sarcocystis, the parasitic worm Diphyllobothrium mansonoides, and the nematodes Dirofilaria immitis, Capillaria aerophila, Physaloptera sp., Strongyloides sp. and others. Of these, D. mansonoides and adult C. aerophila were causing diseased symptoms. [ 111 ] By contrast, pivotal bears have few parasites ; many parasitic species need a secondary, normally planetary, host, and the arctic hold ‘s animation style is such that few alternative hosts exist in their environment. The protozoal Toxoplasma gondii has been found in arctic bears, and the nematode Trichinella nativa can cause a dangerous infection and refuse in older diametric bears. [ 112 ] Bears in North America are sometimes infected by a Morbillivirus similar to the canine distemper virus. [ 113 ] They are susceptible to infectious canine hepatitis ( CAV-1 ), with free-living black bears dying quickly of encephalitis and hepatitis. [ 114 ]
relationship with humans
conservation
In modern times, bears have come under pressure through impingement on their habitats [ 115 ] and illegal trade in bear parts, including the asian bile have a bun in the oven market, though hunt is nowadays banned, largely replaced by farming. [ 116 ] The IUCN lists six hold species as vulnerable ; [ 117 ] even the two least concern species, the brown university bear and the american black wear, [ 117 ] are at hazard of ablation in certain areas. In general these two species inhabit distant areas with little interaction with humans, and the main non-natural causes of deathrate are hunting, trapping, road-kill and ravage. [ 118 ] Laws have been passed in many areas of the universe to protect bears from habitat destruction. public perception of bears is frequently positive, as people identify with bears due to their omnivorous diets, their ability to stand on two legs, and their symbolic importance. [ 119 ] Support for bear protective covering is far-flung, at least in more affluent societies. [ 120 ] The giant lesser panda has become a global symbol of conservation. The Sichuan Giant Panda Sanctuaries, which are home plate to around 30 % of the angry lesser panda population, gained a UNESCO World Heritage Site appointment in 2006. [ 121 ] Where bears raid crops or assail livestock, they may come into conflict with humans. [ 122 ] [ 123 ] In poorer rural regions, attitudes may be more shaped by the dangers posed by bears, and the economic costs they cause to farmers and ranchers. [ 122 ]
Attacks
respective bear species are dangerous to humans, particularly in areas where they have become used to people ; elsewhere, they broadly avoid humans. Injuries caused by bears are rare, but are widely reported. [ 124 ] Bears may attack humans in response to being startled, in defense of young or food, or even for predatory reasons. [ 125 ]
Entertainment, hound, food and folk music music
Bears in captivity have for centuries been used for entertainment. They have been trained to dance, [ 126 ] and were kept for baiting in Europe at least since the sixteenth hundred. There were five bear-baiting gardens in Southwark, London, at that clock ; archaeological remains of three of these have survived. [ 127 ] Across Europe, mobile Romani bear handlers called Ursari lived by busking with their bears from the twelfth hundred. [ 128 ]
Bears have been hunted for sport, food, and folk music medicine. Their meat is dark and ropy, like a bully trimmed of gripe. In yue cuisine, digest paw are considered a dainty. Bear kernel should be cooked thoroughly, as it can be infected with the parasite Trichinella spiralis. [ 129 ] [ 130 ] The peoples of eastern Asia use bears ‘ body parts and secretions ( notably their gallbladders and bile ) as depart of traditional taiwanese medicine. More than 12,000 bears are thought to be kept on farms in China, Vietnam, and South Korea for the production of bile. Trade in bear products is prohibited under CITES, but bear bile has been detected in shampoo, wine and herb tea medicines sold in Canada, the United States and Australia. [ 131 ]
cultural depictions
Bears have been popular subjects in artwork, literature, folklore and mythology. The trope of the mother bear was prevailing throughout societies in North America and Eurasia, based on the female ‘s idolatry and protective covering of her cub. [ 132 ] In many native american cultures, the behave is a symbol of metempsychosis because of its hibernation and re-emergence. [ 133 ] A widespread impression among cultures of North America and northern Asia associated bears with shaman ; this may be based on the hermit nature of both. Bears have thus been thought to predict the future and shaman were believed to have been able of transforming into bears. [ 134 ] There is evidence of prehistoric bear worship, though this is disputed by archaeologists. [ 135 ] It is possible that give birth worship existed in early taiwanese and Ainu cultures. [ 136 ] The prehistoric Finns, [ 137 ] siberian peoples [ 138 ] and more recently Koreans considered the give birth as the spirit of their forefathers. [ 139 ] Artio ( Dea Artio in the Gallo-Roman religion ) was a celtic hold goddess. attest of her worship has notably been found at Bern, itself named for the give birth. Her list is derived from the Celtic give voice for “ digest ”, artos. [ 140 ] In ancient Greece, the archaic cult of Artemis in bear shape survived into classical music times at Brauron, where young athenian girls passed an initiation good as arktai “ she bears ”. [ 141 ]
The constellations of Ursa Major and Ursa Minor, the great and little bears, are named for their supposed resemblance to bears, from the time of Ptolemy. [ boron ] [ 8 ] The nearby star Arcturus means “ defender of the bear ”, as if it were watching the two constellations. [ 143 ] Ursa Major has been associated with a give birth for angstrom a lot as 13,000 years since Paleolithic times, in the widespread Cosmic Hunt myths. These are found on both sides of the Bering estate bridge, which was lost to the sea some 11,000 years ago. [ 144 ] Bears are popular in children ‘s stories, including Winnie the Pooh, [ 145 ] Paddington Bear, [ 146 ] Gentle Ben [ 147 ] and “ The Brown Bear of Norway “. [ 148 ] An early translation of “ Goldilocks and the Three Bears “, [ 149 ] was published as “ The Three Bears ” in 1837 by Robert Southey, many times retold, and illustrated in 1918 by Arthur Rackham. [ 150 ] The Hanna-Barbera character Yogi Bear has appeared in numerous amusing books, animated television shows and films. [ 151 ] [ 152 ] The Care Bears began as greet cards in 1982, and were featured as toys, on clothe and in movie. [ 153 ] Around the global, many children—and some adults—have chemise bears, stuffed toys in the form of bears, named after the american statesman Theodore Roosevelt when in 1902 he had refused to shoot an american blacken bear tied to a tree. [ 154 ] Bears, like other animals, may symbolize nations. The russian Bear has been a coarse national personification for Russia from the sixteenth century ahead. [ 155 ] Smokey Bear has become a function of american culture since his insertion in 1944, with his message “ only you can prevent forest fires ”. [ 156 ]
Organizations
Juvenile giant panda at the Chengdu Research Base of Giant Panda Breeding The International Association for Bear Research & Management, besides known as the International Bear Association, and the Bear Specialist Group of the Species Survival Commission, a separate of the International Union for Conservation of Nature focus on the natural history, management, and conservation of bears. Bear Trust International works for wild bears and other wildlife through four kernel program initiatives, namely Conservation Education, Wild Bear Research, Wild Bear Management, and Habitat Conservation. [ 157 ] specialization organizations for each of the eight species of bears global include :
- Vital Ground, for the brown bear[158]
- Moon Bears, for the Asiatic black bear[159]
- Black Bear Conservation Coalition, for the North American black bear[160]
- Polar Bears International, for the polar bear[161]
- Bornean Sun Bear Conservation Centre, for the sun bear[162]
- Wildlife SOS, for the sloth bear[163]
- Andean Bear Conservation Project, for the Andean bear[164]
- Chengdu Research Base of Giant Panda Breeding, for the giant panda[165]
See besides
Notes
- ^[38] as Treating pinnipeds as marine mammals
- ^ Ἄρκτος μεγάλη (Arktos Megale) and Ἄρκτος μικρά (Arktos Mikra), the great and little bears.[142] Ptolemy named the constellations in Greek : ) and ), the capital and little bears .
References
bibliography
further reading
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