These three-week-old panda twins are rare. Born in the Wolong Nature
Reserve in China at the beginning of September, they are the first panda
cubs known to have survived as a pair without help from humans. Although
female pandas often give birth to twins, only one cub usually survives.
This is odd, given that the panda is closely related to bears, which produce
large litters with little difficulty.
One theory is that the panda’s litter is an evolutionary ‘leftover’
from the time when it was more bear-like in its feeding habits. Unlike bears,
pandas survive on a low-energy diet of bamboo and do not hibernate, so they
have no great fat reserves to draw on when raising their young. Perhaps
to offset this, panda cubs are much smaller than bear cubs. They are almost
fetus-like at birth. How the mother of this pair managed to keep both cubs
alive is a mystery. Researchers at the Wolong Nature Reserve were able to
monitor the cubs for only about three weeks before the mother moved them
to a new, secret den.