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The
Bear Facts - General bear information
and
issues |
Natural History
The bears we know today actually have as their
ancestors bears that have been evolving for some 40 million
years. Fossils of the earliest true bear, Ursavus elemensis,
have been found from the Miocene Epoch in what was then sub-tropical
Europe, and show a small dog-size animal with characteristics
that show a blending of dog and bear traits. It is believed
that all modern bears stem from Ursavus elemensis.
Two important primitive bears that should be mentioned are Arctodus
simus, the giant short-faced bear, and Ursus speleaus,
the European cave bear. The giant short-faced bear is the largest
land carnivore that ever lived. It had extremely long legs,
sharp claws and a reach of over 14 feet tall. It is believed
that this ancient giant is related to today's small-sized Andean
bear. The cave bear, while feared and worshipped by Neanderthal
culture, was actually a herbivore by nature. Cave bears survived
two ice ages but were eventually became extinct, leaving a wealth
of fossils that helped excite the early paleontologists of the
19th Century.
From the ancient cave bears evolved the brown bear, Ursus
arctos, the American black bear, Ursus americanus
and the Asiatic black bear, Selenarctos thibetanus.
And from the brown bear evolved the newest species of bear (only
20,000 years old) the polar bear, Ursus maritimus.
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The
Great Panda Puzzle 
The giant panda, Ailuropoda melanoleuca, has given
scientists the hardest job of proper classification. When
the giant panda was first seen outside of China, scientists
thought it should be placed with the red panda, Ailurus
fulgens, somewhere in the raccoon family. Both pandas
feed on bamboo and have long wrist bones that work like human
thumbs to grip the plant. The bones and teeth of the giant
panda resemble those of red pandas far more closely than any
bear relative. Today's methods of examining and comparing
gene sequences between species place the giant panda firmly
in the bear family, but certainly the earliest species to
evolve from Ursavus elemensis, the first true bear
ancestor.
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When Is a
Bear Not a Bear?
Two animals are often confused as being part of the ursid or
bear family but in fact are distinctly different creatures.
The cuddly koala, Phascolarctos cinereus, of Australia
is actually a marsupial, complete with a pouch for carrying
for its young and is related to kangaroos. Binturongs, Arctictis
binturong, from Southeast Asia often carry the confusing
nickname of "bearcat" but are members of a group of
animals called Viverridae that includes linsangs, civets and
genets. |
Andean bear (Tremarctos ornatus)
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Meet the Family
The following brief descriptions should help differentiate today's
existing eight bear species, with their varied habitats, ranges,
diets and characteristics.
The largest bear species existing today is either the polar
bear or the brown bear, depending upon the criteria one chooses.
The polar bear is the heaviest, weighing up to 1,500 pounds
but its narrow silhouette, well adapted for swimming, make it
appear smaller than the longer and more robust brown bear. Males
of all bear species are usually larger than the female, sometimes
as much as 50% larger.
Sun bears are the smallest of the eight bear species. They weigh
between 60 - 145 pounds and are
48 - 60 inches in length.
Giant pandas are also small bears. They weigh up to 275 pounds
with a body length of 64 to 76 inches.
Andean bears can weigh between 140 - 340 pounds and have a body
length of 60 - 72 inches. The male Andean bear can be up to
40% larger than the female.
Asiatic Black Bears are medium sized bears with a body length
of 50 - 74 inches and weigh between
220 - 440 pounds.
Sloth Bears are also medium sized bears. They weigh between
175 - 310 pounds and a body length of
60 - 75 inches.
American Black Bears are medium sized bears. They weigh between
130 - 660 pounds and are
50 - 75 inches in length.
Brown Bears are one of the largest species of bears. They weigh
between 300 - 860 pounds and can be up to 9' 6" in total
body length.
Polar Bears are considered to be the largest. They weigh between
440 - 1760 pounds and have a body length of about 8' 5".
Note:
length - measured from the tip of the nose to the tip of the
tail
height - measured from the bottom of its paw flat on the ground
to the highest point of the shoulder |
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