Sun Bear (Helarctos malayanus)
Reproduction and Behavior
As the Malayan sun bear becomes increasingly endangered, it’s
reproductive and behavioral patterns become harder to track.
Knowledge is limited on the sun bear’s reproduction and behavior
traits. As the Malayan sun bear moves from the Vulnerable
Species List to the Endangered Species List, more drastic steps
will have to be taken in order to keep this species of bear
extant (ICUN Redlist of Threatened Species).
Since Malayan sun bear’s tend to live in isolated environments.
They are rarely seen interacting with other species and even
interaction among the same species is limited. They have been
seen feeding briefly in the same area and even rarely from the
same tree (Biological Conservation). The only other time the sun
bear’s interact with one another is when they are seeking a
mate. The female bear will vocalize when she is ready to mate
and when a male bear responds the sexual encounter takes place
briefly before both bears go their separate ways. The sun bear’s
mating season isn’t on a distinct cycle like the mating seasons
of most other species. The constant, annual environment of
Southeast Asia allows the sun bear to reproduce year-round.
Although the sun bear is capable of reproducing throughout the
year, a mother sun bear only tends to have one cub a year
(Biological Conservation). On a few rare occasions a mother sun
bear is believed to have become pregnant twice in a
given year, but this again is rare. The warm habitat in which
they live also
means that the sun bear doesn’t need to hibernate like other
bear species in the cooler climates (Biological Conservation).
Although sun bears have been seen out searching for food during
the day, they tend to be nocturnal. They have a sensitive nose
that can help lead them locate their food source, even in the
dead of night. This is characteristic is important to sun bears,
because their eyesight is poor (Journal of Tropical Ecology).
Since female sun bear’s tend to raise their cubs alone, the
mother is forced to provide not only for herself, but for her
cub as well. The Malayan sun bear is very protective over her
offspring. The sun bear is considered to be the least
aggressive of the bear species, but when it comes to her cubs
their aggressive tendencies come out (Biological Conservation). A mother
sun bear will
fight to the death in order to protect her cub. She will not
only risk her life, but a mother sun bear puts her own
well-being before her offspring. A mother sun bear always feeds
her cub before she will eat. If food supplies are scarce this
could be detrimental for the mother. This is why mother sun
bears are sometimes seen scavenging during the day, not far from
the den where their cub is sleeping (Biological Conservation). It is important that a
mother sun bear gets an adequate amount of food, because raising
a cub to an age where they can live independently is
metabolically expensive.
A mother sun bear tends to have between one and two cubs in a
given reproductive cycle, usually one cub is most common. On a
few rare occasions a mother has had up to three cubs at a time. A
mother sun bear can reproduce year-round, but usually only
becomes pregnant once a year. This is because the gestation
period in a female sun bear ranges anywhere from 95 to 240 days
(3 months to 9 months), which is considerably less then humans
(Biological Conservation).
One particular mother on file gave birth to 2 cubs in one year!
This again is rare. A cub usually becomes independent anywhere between
one and two years of age, this ranges from mother to mother and
from cub to cub (Biological Conservation). From here on out they provide completely for
themselves and have little to no interaction with other sun
bears until they are ready to mate. Male and female sun bears
reach reproductive maturity at about the same time. Studies show
that this is around 3 years of age The mother will continue to
live in solitude with her cub, until her cub able to care for
itself. Female sun bears continue to reproduce well into their
adult lives. A sun bear’s life expectancy ranges anywhere from
25 years to 35 years and females have been known to reproduce up
until their mid-twenties (Biological Conservation).
When the cub is finally ready to start learning a mother takes
him or her out of the den and slowly introduces the cub to its
surroundings. These first few interactions consist of
exploration and play. Slowly the mother begins to teach the cub
by example. As the cub matures he or she begins to follow this
example, feeding and caring for itself. A mother sun bear will
teach a cub everything from feeding strategies to tree climbing before the
cub is old enough to live on it’s own (Ecology of the Malayan
Sun Bear).
When a female sun bear gives birth the tiny cub is blind and
hairless. Within days, the cub will open it’s eyes and within
weeks it will develop a thin film of hair covering it’s skin.
The warm environment of Southeast Asia allows for the cub to
keep warm for a the few hours of the day that the mother is out
hunting (Ecology of the Malayan Sun Bear). One difficult aspect of the Southeast Asian environment
is the threat that the rainy season brings. The den of the cub
is best kept dry. If the cub is drenched in water and the
temperatures drop at the night, the chills can be fatal to
the
newborn. For this reason, a mother usually builds a den at a
higher altitude. The cub then remains in the den for the next
few weeks where the mother sun bear nurses her cub with milk
from her teats (Biological Conservation).