ABOUT THE BEARS: Bears of the World

Bears are mammals belonging to the order Carnivora and grouped within the family Ursidae. The extant species (species existing in the present time) of this family are divided into three large groups: subfamily Ursinae, which includes the Polar bear (Ursus maritimus), Brown bear (Ursus arctos), American black bear (Ursus americanus), Sloth bear (Melursus ursinus), Asiatic black bear (Ursus thibetanus) and the Sun bear (Helarctos malayanus); the subfamily Tremarctinae, whose only representative is the Spectacled bear (Tremarctos ornatus) and the subfamily Ailuropodinae, whose only representative is the Panda bear (Ailuropoda melanoleuca).

Among the eight extant species, five (American black bear, Brown bear, Asiatic black bear, Sun bear and Spectacled bear) are omnivores and ingest a large gamma of foods, from tender green vegetation, fruits, roots, insects, amphibians and birds, to even other mammals.

The remaining three species have more specialized diets, the Polar bear being basically a carnivore, the Panda bear an herbivore and the Sloth bear an insectivore. However, these species also consume other kinds of foods depending on the availability of the resources.

In the present time, we find bears in the continents of America, Asia and Europe, with the Spectacled bear being the only species with a significant presence in the Southern Hemisphere.

In all the bear species, the male is larger than the female (sexual dimorphism) Nonetheless, this difference varies depending on the species and the locality.

Species	Size Difference
Polar bear	Males 25-45 % larger
Brown bear	Males 35-50 % larger
American black bear	Males 33 % larger
Sloth bear	Males are slightly larger
Asiatic black bear	Males are slightly larger
Sun bear	Males 10-15 % larger
Spectacled bear	Males 33 % larger
Panda bear	Males 10-20 % larger

The largest of the bear species are the Brown bear and the Polar bear. Individuals of certain sub-species (geographic race) of Brown bears can grow up to 10 feet tall (from the tip of its nose to the tip of its tail.) The smallest species of bear is the Sun bear with an average size of only three feet.

Species	Average Male Size
Polar bear	8.4 feet
Brown bear	7 – 10 feet
American black bear	6 feet
Sloth bear	5 – 6 feet
Asiatic black bear	5 – 7 feet
Sun bear	3 – 5 feet
Spectacled bear	7 feet
Panda bear	5 feet

Bears are plantigrades; this means that they completely rest the sole of their feet on the surface they walk on. Bear’s paws are equipped with five toes that exhibit sharp and curved claws. They are particularly important, as thermal regulation (corporal heat regulation) is done mostly through them. The hind paw are larger than the fore and the footprints left behind very much resembles a human print, with the difference that it leaves a specular image with the large toe pointing towards the exterior of the footprint.

The general believe is that bears must have very poor vision. This is due to their behavior of standing upright on their hind paws while approaching objects that catch their attention. However, this is not apparently so in all species. For instance, the Polar bear has eyes as large as humans, having a pair of extra eyelashes to help them filter the sunlight reflected on the snow. Their depth perception is also excellent, being able to detect a stationary object on the snow at more than 1 Km. away. Furthermore, thanks to a protective membrane, they are also capable of excellent underwater vision.

The size and position of the ears varies according to the species, anywhere from long, large and slanted like the Sloth bear, to very small like the Polar bear. The bear’s hearing is apparently good.

Smell is the most important sense for bears. It allows them to identify other individuals, to prevent danger and to procure food. The species of bear exhibiting the most acute sense of smell is the Polar bear, which has been reported to spot a prey more than ten (10) Km. away.

Bears are curious and intelligent creatures that can also be dangerous under certain circumstances. They appear to be slow and uncoordinated when in reality they’re fast and agile. Some are skillful climbers, such as the Spectacled bear and the Sun bear.

Bears are often given human qualities and there are logical fundaments that explain this appreciation. When we study in detail some of the aspects of the biology of these animals, we come to understand that their ability to walk upright for some periods of time on their hind legs; their extraordinary quality to detect intruders barging into their territory by means of their highly developed sense of smell and perception; the shape of the hind leg’s footprint, which highly resemble human ones; their ability to manipulate objects and to bend the elbows in their front legs; the way in which female bears nurse their cubs by supporting them between their front legs while resting them in their stomach, and finally, their particular food preferences (it is rumored that some tribes indigenous to North America and Eurasia, learned to survive in the mountains by paying attention to the bear’s diet) .

At the present time five (5) species of bear are threatened with extinction due to factors associated with human activities.

Threat categories according to the (IUCN) World Conservation Union) (*). List of threatened species listed in CITES (**).

Polar Bear (Ursus maritimus)

It’s the largest of the living carnivores and a symbol of the gelid Artic to all the nations of the world.

The Inuit (Eskimo tribe) have incorporated it to their cultural values since ancestral times.

Polar bears are not endangered, although their conservation is dependant on attentive vigilance and international agreements.

(*) LOWER RISK (LR), Conservation Dependent (cd).

(**) APPENDIX II.

Brown bear (Ursus arctos)

Of all bears, the Brown bear occupies the largest territory worldwide. Because of this, it has diversified into a large number of sub-species, with one located in Kodiak island, Alaska (Ursus arctos middendorffi) being the largest.

In spite of being out of danger worldwide, in some regions is nearly extinct, such as in the case of Western Europe and South Asia. In Mexico it disappeared in the mid twenty century.

(*) LOWER RISK, Least Concern (lc).

(**) APPENDIX II, APPENDIX I (Mongolia and China).

Andean or Spectacled bear (Tremarctos ornatus)

It’s the only representative of the bear family in South America. During Pre-Colombian times, it occupied an important place among the cultures living in the Andean mountain range. However, in the present day it’s hunted down because of false beliefs and deemed one of the most threatened bears in the world.

(*) VULNERABLE (VU).

(**) APPENDIX I.

American black bear (Ursus americanus)

Even though its name indicates a characteristic associated with color, this shouldn’t be used literally when referring to this species, as their coloration changes among individuals and regions. There are even populations of “white” black bears located on an island of British Columbia, Canada. The black bear’s image has been popularized around the world through innumerable stories and cartoon characters.

The Black bear wild population is still viable and the strategies developed for their study and conservation have served, as models to better understand the ecology of other species of bears.

(*) LOWER RISK, Least Concern (lc).

(**) APPENDIX II.

Sloth bear (Melursus ursinus)

Their appearance is different than that of all other bears; as a profuse coat covers their bodies protecting them against ant and termite bites which constitute their main source of food. In the last decades, traditional Chinese medicine has caused an alarming decline of the population of this species by attributing curative qualities to some parts of the animal.

(*) VULNERABLE (VU).

(**) APPENDIX I.

Asiatic black bear (Ursus thibetanus)

Their domains are the forests of the Himalayan mountain ranges where it reveals itself in very rare occasions.

Just like the other Asiatic bears, they are victims of the international illegal trade of bear parts feeding the black market for traditional Chinese medicine.

In the present day, their populations are threatened and almost extinct in Japan and in the south of Russia.

(*) VULNERABLE (VU).

(**) APPENDIX I.

Panda bear (Ailuropoda melanoleuca)

This charismatic bear is the world’s symbol for natural conservation. Their habitat is limited to the bamboo forests of central China.

In spite of the large efforts to achieve their preservation, the Panda continues to be in the endangered of extinction list with less than 1000 individuals in the wild.

(*) ENDANGERED (EN).

(**) APPENDIX I.

Sun Bear (Helarctos malayanus)

This bear is the smallest of all. It continues to be an enigma to the scientists, which haven’t been able to study it in its intricate habitats situated in the rain forests of the Asiatic Southeast.

Their population’s status is unknown at this time, but presumed to be threatened due to the destruction of their habitat, the illegal trade of bear cubs and hunting, which supplies the demands for traditional Chinese medicine.

(*) DATA DEFICIENT (DD).

(**) APPENDIX I.

Credits in Photos:

- All the photos in this page were taken from the CD-ROM "BEARS & PANDAS of the world", with exception to: