Quick Fire Science: Giant panda breeding
Here's Dominic Ford and Kate Lamble with this week's Quick Fire Science.
- Giant pandas are native to only a small mountainous region in central China. There are thought to be no more than 3,000 of the animals remaining in the wild, and 300 living in captivity.
- Bamboo makes up 99% of a panda's diet, but its nutritional value is so poor that each animal must eat between 30 and 60 kilograms each day.
- That bamboo also contains so much fibre that panda may need to... empty their bowels... up to 40 times a day.
- To compound the problem, pandas have a digestive system similar to that of other bears, adapted for eating meat rather than a vegetarian diet.
- Their poor diet means that mother pandas have little energy to spare on raising cubs, and their babies are tiny and almost completely helpless at birth.
- Even after a year, panda cubs have typically grown to only a third of their full adult weight.
- In the womb, panda foetuses are unusual in that they do not implant until several weeks into the pregnancy, making it difficult to tell whether a female is pregnant.
- Normally a spike in the hormone progesterone a few weeks before birth tells vets that a female is expecting, but while Tian Tian - the panda in Edinburgh zoo - had such a spike last month, her hormone have since shown contradictory signs.
- Breeding captive pandas is especially difficult as males usually fight over females in the wild, and this seems essential to building up a male's libido.
- Moreover, female panda only ovulate once a year, meaning that there is only a 36-hour window each year in which she can become pregnant.
- Pandas have become endangered because of habitat loss in China due to more intensive farming.
- Even though there are now extensive conservation efforts, their slow rate of breeding means populations grow incredibly slowly.
Zoo keepers in Edinburgh have said this week that they're uncertain whether a giant panda in the city's zoo might give birth to a cub. But why is it so notoriously difficult to get pandas to breed in captivity, and how can there be so much doubt over whether a panda is pregnant?