Zoos often take care of animals that have been injured in the wild or displaced from their natural homes. Wild tigers and lions are rescued from the plains of Africa. Monkeys and gorillas are taken in to study because they are much like us. The pandas in China are an endangered breed and are kept in captivity to help them reproduce. Elephants are threatened out in the wild by poachers looking to sell the ivory from their tusks.

The San Diego Zoo is home to a new California condor chick born March 11, 2013. The California condor has long been an endangered species. Thanks to its reproduction program, it has fostered many newborns on the endangered species list.

The Bronx Zoo is the largest you will find in a metropolitan location in the US. In 2012, a young man jumped into the Tiger den and was mauled. He lived and is currently on trial for trespassing.

The Detroit Zoo is famous for having cageless exhibits where the animals are grouped by continent.

The oldest zoo in the United States, Lincoln Park Zoo in Chicago remains one of the most popular zoos and has a varied collection of about 2000 animals.