There is a long-standing debate about whether zoos are good or bad for animals. Take this quiz to learn both sides of the issue.
Ancient Egyptian records from 1250 B.C. describe birds, lions, and giraffes in captivity.
In the early 13th-century, King Henry III of England charged a small fee for the public to view his family menagerie in the Tower of London.
The Imperial Menagerie in Vienna, Austria, was established in 1752.
Zoo Berlin in Germany has more than 15,000 animals.
All zoos and animal exhibiters in the U.S. require a license from the Department of Agriculture.
It is a difficult question to answer and depends on your point of view -- and also on the particular animal.
In basic terms there is usually a more natural habitat, with moats separating animals and people instead of steel bars and cement cages.
Captive breeding programs help restore the numbers of endangered species.
They rebuilt a population of fewer than two dozen birds to around 170 birds in a 10-year period.
The Pere David's deer was extinct, but the Chinese and European zoos' breeding programs enabled four of the deer to be released into the wild, where they are now self-sustaining.
Some zoos provide a refuge for abandoned animals or those rescued from danger.
Zookeepers now understand that animals such as monkeys, bears and elephants need engaging activities to prevent boredom and mental deterioration.
The Bronx Zoo has channeled more than $3 million toward conservation projects in central Africa.
A zoo teaches people about the needs of animals and promotes the importance of conservation.
In the wild elephants can wander as much as 30 miles (48 kilometers) a day in large groups. In a zoo, there are only a few elephants with just a few acres to roam.
They starved to death because of insufficient or incorrect food.
Although the habitats may resemble those in the wild, roaming space even in a large zoo is far more limited than what the animal is accustomed to in the wild.
Many animals display signs of serious distress: bears pacing back and forth, wild cats obsessively grooming themselves and elephants bobbing their heads.
Not at all: Of the 145 reintroduction programs carried out by zoos in the last century, only 16 really succeeded in restoring populations to the wild.
According to some studies, many zoo visitors are busy talking to each other about unrelated subjects and pay little attention to the animals.