How Long Do Animals Live?
The lives of animals range from several hours to many years. An adult mayfly lives only a few hours. The giant tortoise may live more than 150 years. The other animals are in between. A mouse will live only two or three years, as do rats, bats and moles.
Dogs and cats are old when they reach the age of 12, but some live longer. Horses may live as long as 40 years, but usually less. And parrots have been known to live more than 50 years. Elephants grow old at just about the same rate as people. Many of them live to be 65 or 70.
Captive animals are protected from drought, flood, fire, and predators; they are fed regularly; and if injured or exposed to disease, they receive medical attention. This care helps them to live long, healthy lives. However, wild animals do not have these advantages. They live only as long as they are able to defend themselves and find food.
Determining the age of wild animals is very difficult, but research is producing some of the answers. Fisheries biologists have learned to read the growth rings formed in the scales, fin spines, ear bones (otoliths), and vertebrae of fish to determine age.
Biologists can determine the age of some mammals by studying their teeth. The number and type of teeth indicate age in sheep and goats, but wear on the jaw teeth reveals a deer’s age.
Zoologists once believed whales lived 150-200 years, but the waxlike earplugs from hundreds of whales caught in the Antarctic fishing grounds show that none of the whales was more than 60 years old.
Trying to keep track of a wild bird to see how long it actually lives would be next to impossible; however, ornithologists have been able to age some wild birds from information received through banding efforts.
Animal size does not necessarily indicate life span. The wild lion’s age compares with that of a domestic cat; larger breeds of dogs have shorter life spans than smaller ones; and a Shetland pony can outlive a regular horse.
However, larger animals, as a rule, do live longer in the wild than smaller ones. One reason for this is that more dangers face the smaller creatures.
Smaller animals also may live at a faster body pace than larger ones. This means they may breathe faster, have a faster heartbeat, and eat more food in relation to body size to produce the energy required for this faster pace. As a result, the smaller animal’s body wears out faster, like a motor that constantly must be run at high speed.
Activity of a creature also may determine its life span. The queen honeybee, which spends her time laying eggs for the hive, may live as many as five years. Worker bees, on the other hand, live no more than six to twelve weeks.
During this time they are gathering pollen and producing honey. Both the workers and the queen in a colony have long lives for insects. However, the queen termite surpasses them all by living fifty years or more. Centipedes and scorpions live five to six years.