Baby Panda / Evolutionary Biology

It sounds like the baby panda at the National Zoo is still doing well, a much welcome sign of good news for a zoo that has had its share of problems in recent years:

The National Zoo's giant panda cub has doubled in length since his first examination two months ago and could be crawling around within two weeks, the animal park's chief veterinarian said yesterday.

During his seventh medical examination yesterday morning, the cub measured 24.7 inches long, compared with 12 inches during his first exam Aug. 2. He weighed 11.1 pounds, compared with 1.82 pounds at his first checkup.

"He's the incredible expanding panda," said chief veterinarian Suzan Murray.

I have been glued to the story of the baby panda, both because pandas are one of my favorite animals and because I am fascinated by the phenomenon of altricial young, where newborns are so helpless as to require long term care by a parent. Humans (and pandas and elephants) are interesting examples of altricial creatures, since we are also k-selected. K-selected animals tend to have infrequent breeding, long gestation and maturation periods, and precocial young (born with skills, sight, hair, etc).

It does seem a bit strange, after all, that human babies gestate for so long, and yet are born still utterly defenseless, and remain that way for years. Cats gestate for nine weeks, have litters averaging two to five, and a newborn kitten can safely leave its mother after 12 weeks, reaching sexual maturity in six months.

Of course, elephants gestate for 22 months for a single calf and the calf nurses for up to 2 years (at 3 gallons of milk per day!). Like human children, elephant calves learn primarily through observation of adults, not from natural instinct. Elephant calves do, however, stand within an hour after birth and can follow a herd within a few days.

A lot of fascinating stuff out there. The only two science classes I took in college were intro to astronomy, which was less fun than anticipated, and Science B-29, "Human Behavioral Biology", which went (and presumably still goes) by the euphemism "Sex" at Harvard. The latter was one of the more fascinating classes I took, and I have retained a novice interest in the subject.