Gail Proctor, age 8, of Charlotte, North Carolina, for her question:
What is a snake's life span?
A great big boa constrictor may live long enough to enjoy 23 birthdays. But most of our little grass snakes live only about 14 years. We cannot be certain about the exact life spans of the various snakes, because it is very hard to check the ages of snakes in the wild. We can note how long they live in captivity. But these records are not too reliable. Some captive snakes live longer than they would in the wild, others die sooner than they should.
The snakes live very secret lives. Even if they could tell us how old they are, chances are they would refuse to answer. Sometimes the rattling, buttons on the end of a rattlesnake's tail give him away. A young rattler has only two or three buttons. In the prime of life he may have eight. But an old timer often loses a few of the smaller buttons at the tip of his tail so we cannot tell how many he had. For this reason we cannot be certain about a rattler's age.
The problem is much harder with other snakes. As a rule, a baby snake can double his size in a year. After two or three years, he is grown up enough to start a family of his own. But we cannot judge his age from his size, because he does not grow while he hibernates. If he sleeps half the year, he is smaller than he should be and looks younger than he actually is.
We can put markers on birds and other wild animals. When we find them later, we can learn a little about their life spans. But there is no fair way to mark a snake. Besides, even if we did find a way, chances are we would never find him again to check the passing years. After all, snakes try very hard to keep out of sight.
It is easier to check the ages of snakes that live in zoos. There are many records of how long they live in captivity. Some are born in zoos and live their whole lives there. They give us a fair idea of the life spans of their relatives in the wild. One of these records goes to a boa constrictor who was born in captivity on July 14, 1900. After 23 years of pampering, he died of old age. The old timer measured 13 feet plus two inches. Most likely 23 years or so is the normal life span for big boas in the wild.
In captivity, the larger types tend to live longer than the smaller snakes. The little garter snakes and grass snakes seem to have life spans of 12 to 14 years. But the medium sized water snakes hardly ever live more than two or three years in captivity.
We know how long certain snakes can live in captivity, where they get plenty of food, plus warmth and moisture. But life in the wilds is very risky and few snakes get a chance to live as long as they otherwise could. Baby snakes are devoured by herons and hawks, opossums, badgers and many other hungry enemies. The mongoose and certain eagles kill snakes of all sizes. But their worst enemies are those people who think that every kind of snake should be destroyed on sight.