THE
LIFE SPAN OF ANIMALS
Signs of senility, or extreme old age, are seldom seen in the wild. Animals
living under natural conditions rarely approach their maximum possible age because of very high death rates due to infant
mortality, diseases, predators, bad weather, accidents, or competition for food and shelter. For this reason, most of the
reliable information about the length of the life span comes from zoos, where accurate records are kept and animals live under
conditions almost ideally suited to prolong life. A mouse whose life is measured in months in the wild can survive years of
captivity.
Large animals tend to live longer than their smaller relatives -- but there
are many exceptions. For example, man is longer-lived than any other mammal. After him, in age, comes the elephant, hippopotamus,
horse, rhinoceros, the bears, the big cats and many others which are larger in size. In general, birds live longer than mammals,
and certain reptiles the longest of all. A giant tortoise is known to have lived 152 years on the island of Mauritius and
then was killed accidentally or it might have lived a century longer. Even our common box turtle rather frequently reaches
the 50-year mark. It is an interesting sidelight that there seems to have been no change in the life span of dogs, cats, horses
and cows under thousands of years of domestication by man.
The following examples of extreme old age have been chosen from the reliable
records of zoos and aquariums all over the world.
MAMMALS - YEARS
Elephant - 69
Horse - 50
Hippopotamus - 49
Chimpanzee - 40
Grizzly
Bear - 32
Bison - 30
Lion - 30
Tiger - 25
Elk - 22
Mountain Lion - 20
Beaver - 19
Wolf - 16
Squirrel
- 16
Chipmunk - 12
Cottontail - 10
House Mouse - 4
BIRDS - YEARS
Turkey Buzzard - 118
Swan - 102
Parrot - 80
Great
Horned Owl - 68
Eagle - 55
English Sparrow - 23
Canary - 22
Humming Bird - 8
REPTILES - YEARS
Giant Tortoise - 152
Box Turtle - 123
Alligator - 68
Snapping
Turtle - 57
Cobra - 28
Cottonmouth - 21
AMPHIBIANS - YEARS
Giant Salamander - 55
Toad - 36
Bullfrog - 30
Mud
Puppy - 23
Green Frog - 10
Newt - 7
FISH - YEARS
Catfish - 60
Eel - 55
Carp - 47
Mosquitofish
- 2
INSECTS - YEARS
Cicada - 17
Ant (queen) - 15
Locally, in the Lincoln Park Zoo, for instance, the Indian elephant, "Judy",
died at 51. "Bushman", the famous gorilla, died there at 23 years and a pelican at 52.
When the Shedd Aquarium was under construction in 1929 workmen, for a joke,
stocked the central pool with carp. Twenty Eight years later, three or four of them still survived.
Among the native wildlife in our Trailside Museum a gray squirrel has lived
16 years, a barred owl 15, a blue jay and a chipmunk each 12 years.
At the Brookfield Zoo, the pair of chimps, "Mike" and "Sally" died at 35
and 37 years old, respectively. They still have the same alligator snapper and "Cookie" the Cockatoo with which they opened
in 1934. Dozens of birds have lived 18 to 20 years and hundreds 8 to 15 years. A spitting cobra died after 23 years in the
zoo.
Why do some animals hibernate in the winter?
Grizzly black bears,
hummingbirds and squirrels hibernate in the winter because a long, chilly season of little food and warmth is no picnic for
these animals.
Unlike the warm seasons of spring and summer that provide an unlimited
amount of food for these critters, the winter season only provides a cold, frozen ground where food is extremely scarce.
In addition, the wintry days are frigid and short while the hours in
the dark night seem to drag on for a chilly eternity. Searching for grub often leaves the stomachs of these animals
empty because by the end of their search their bodies end up burning more calories than the animals get back from the food
when and if any is found.
So instead of starving or freezing to death, these animals decide to
pack in all in for the long haul and hibernate during the winter months. Hibernation helps these animals survive in the roughest
and toughest conditions. By hibernating, an animal decreases its body.s energy needs to a bare minimum. Hibernation is a process
of lowering an animals body temperature and slowing down its heartbeat into order to conserve energy during times of scarcity
and stress.
Every animal hibernates in different ways. While squirrels can wake up
every four days to grab a bite to eat and take a trip to the bathroom, black bears can stay dormant, or inactive, for up to
seven months with no food, water, or visits to the bathroom.
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