Although
sometimes known as the native bear, the koala is in
fact no relation to the bear family.
The koala is a nocturnal, tree dwelling marsupial mammal,
which feeds almost exclusively on the leaves of a few
species of eucalypt.
Koala babies are only about 19mm when born, but they
can still climb into mother's warm pouch, where they
stay for about five to six months, after which time
they spend another three to four months clinging to
her back with their strong claws while she travels from
tree to tree or when she is resting, cuddled up in her
arms.
Koalas are very fussy eaters, feeding almost entirely
on eucalypt leaves. Koalas seldom drink, as they obtain
enough water from the diet of leaves.
The Koala sleeps in the fork of a tree for most of the
day and moves about and feeds at night. It is most active
just after sunset. The Koala can sleep for up to 20
hours per day, mainly because their diet is so energy
poor.
Sleeping allows them to conserve their energy.
Birth
and Pouch Life
Usually,
koalas produce only a single young, rarely twins are
born.
At birth, the young is about 19 mm in length and weighs
about 0.5 g.
At 7 weeks, the young has a head length of about 26
mm. The head is large in proportion to the rest of the
body. By 13 weeks, the
young has attained a body weight of about 50 g and a
head length of 50 mm. At about 22 weeks of age, the
eyes open and the young begins to poke its head out
of the pouch for the first time.
By 24 weeks of age, the cub is fully furred and the
first teeth errupt.
At
30 weeks, the cub weighs about 0.5 kg and has a head
length of 70 mm. It now spends most of the time out
of the pouch clinging to the mother's belly. Some 6
weeks later, the cub weighs 1 kg and no longer enters
the pouch. It spends much of the time sitting on the
mother's back, but returns to the mother's belly in
cold, wet weather and to sleep.
At 37 weeks, the cub moves from contact with the mother;
the excursions were brief and quickly terminated if
the mother moved.
At 44 weeks, the cub still ventures less than a meter
from the mother.
By
48 weeks, the cub is more adventurous and no longer
squeaked when the mother was removed. At this age, mother
and cub are often seen sleeping back to back.
The cub remains with the mother until about 12 months
of age when it weighs a little over 2 kg.
-- From: The Koala: A Natural History by Anthony
Lee & Roger Martin --
Summary
Size:
Size is larger in the southern regions.
Head-body length in the south average 30.7 in./78 cm
for males and 28 in./72 cm for females.
Weight:Average
26 lbs/11.8 kg for southern males and 17.4 lbs/7.9 kg
for southern females.
In the north, males average 14.3 lbs/6.5 kg; females
11.2 lbs/5.1 kg.
At birth young weighs only 0.5 gm.
Coat: Thickest of the marsupials.
Gray to tawny: white on the chin, chest, and forelimbs.
Rump consists of tougher connective tissue dappled with
white patches. Fluffy ears with longer white hairs.
Coat is shorter and lighter in color toward northern
regions. The fur of the koala in southern region is
thick and woolly and is thicker and longer on the back
than on the belly. Koalas in northern region have a
short coat; this gives them a naked appearance. The
color and pattern of the coat varies considerably between
individuals and with age.
Gestation period:34-36
days
Life span: Their life span
today varies considerably due to stress factors, probably
averaging 13-18 years.
Although
sometimes known as the native bear, the koala is in
fact no relation to the bear family.
By
48 weeks, the cub is more adventurous and no longer
squeaked when the mother was removed. At this age, mother
and cub are often seen sleeping back to back. 
