I watched this rather funny video two days ago of a baby panda sneezing which made me want to write about pandas. I know this is going to sound horrible, but after watching several nature shows on pandas over the years, I’m convinced that giant pandas are partially responsible for their own endangered state due to their bizarre and strange evolution. This is what I have learned:
- Pandas are solitary creatures, and they don’t seem particularly inclined to procreate. In captivity (it’s hard to spot and observe pandas together in the wild), you can put a male and female together alone for long periods of time, i.e. years, with enough space and privacy for each of them to feel comfortable, and they often refuse to copulate, even when in heat.
- Pandas used to be carnivores. Their digestive systems are suited to digest meat. Other plant eaters, like deer, can absorb up to 80% of nutrients from plants, but pandas can only absorb about 20% of their nutrients from bamboo. (Pandas’ short intestines are unable digest cellulose and, therefore, do not remove all of the nutrients from the bamboo.) Pandas evolved their characteristic “thumb” and from then on pretty much ate only bamboo stems and shoots which accounts for 99% of their diet. (Couldn’t they have found a happy medium as both carnivore and herbivore? And as herbivores, couldn’t they have diversified their diet just a little and mixed in a few berries and cabbage or something?)
- Because bamboo offers so little nutritional value, the giant panda eats 60-80 pounds of bamboo a day and spends at least 12 hours a day, eating. It also has to defecate a lot (up to 40 times a day) because their digestive systems don’t absorb bamboo well. (So don’t ever ask a panda whether they have anything better to do than pick at leaves.)
- The female panda is fertile only 1 to 3 days a year. Breeding season is from March to May. This doesn’t give a male much opportunity to sow his oats and help ensure survival of the species. Because pandas are solitary and territorial creatures, they usually do not tolerate other pandas in their areas (mostly because it would take too much energy to compete for food), so each adult panda needs approximately 2 to 4 square miles of land in order to survive.
- Once the egg is fertilized, the embryo free floats in the uterus and does not implant itself in the wall of the uterus until 3-5 months later (!) when the cells actually begin to divide and the embryo begins to grow. (Does this make any sense to you? The theory is that the mother has enough resources when implantation happens to keep the baby alive and that conditions are optimal for the embryo’s survival. She has to keep her belly full during this time or else the embryo will likely not implant itself.)
- Female pandas mature into adults around the age of 4 or 5 and males at around the age of 7 or 8. Pandas live for about 20 years in the wild (and 25-30 years in captivity).
- The baby panda is born about the size of a stick of butter (3-6 oz). The mother is about 900x the baby’s weight (about 150 lbs), and mother pandas have been known to not infrequently kill their cubs by accident by rolling over or onto them. Not only is the baby tiny, it’s blind, toothless and furless when it’s born. The baby opens it’s eyes after 6-8 weeks and is physically and fully dependent on the mother for about 5-6 months, after which the baby can start consuming small amounts of bamboo. It’s emotionally dependent on its mother for an even longer time. So the mother usually takes care of the baby panda for something like three years, which means that, on average, a female raises up to two or three cubs during her lifetime. (Males leave after mating and play no role in raising of babies.)
- If the female panda has two babies or twins, which occasionally happens, she will only take care of one cub and allow the other to die soon after birth. (This is probably because the mother has only enough energy to take care of one cub.)
I’m not debating that deforestation or human expansion into panda habitat have made giant pandas one of the most endangered species in the world. But certainly, the panda’s evolution doesn’t seem to have helped their survival as a species.
Today, it is estimated that there are only 1,500 to 3,000 giant pandas in existence. Outside of captivity, they live only in a few high mountain ranges in central China in the provinces of Sichuan, Gansu and Shanxi. Less than a few hundred are in captivity, and human intervention has become instrumental in helping to ensure that pandas survive. Also, several years ago, there was a breakthrough in China on how to maximize the survival of baby pandas in captivity. The mother panda, as mentioned, is only willing to take care of one cub if she has twins, and she uses her acute sense of smell to differentiate between the two cubs. Scientists were able, in some cases, to fool the mother into feeding the rejected cub by rubbing the smell of the accepted cub onto the rejected cub so that the mother might end up feeding both. (Humans would have to do a switcheroo of the two babies.)
As for the human Chinese population, statistics show there are more than 1.3 billion people in China alone, which means that Chinese people constitute a full 20% of the world’s population (or 1 out of every 5 people). And, unlike giant pandas, Chinese people seem willing to eat, well, almost anything.