The death of an elephant at the Los Angeles Zoo has animal rights activists renewing a fight to get these large animals out of confinement.
Elephant exhibits are always among the most popular at zoos nationwide, but those who champion animal rights have long debated with zoo authorities whether elephants' captivity in zoos is humane.
On Saturday, Gita, a 48-year-old Asian elephant, was found sitting when zookeepers went to her yard. Despite medical attention, she died early that morning. A necropsy is under way, but the results will not be available until later this week.
There are currently about 300 African and Asian elephants in U.S. zoos, but one study predicts there will be fewer than 20 zoo elephants remaining within 50 years unless the animals are bred more successfully.
Nearly a dozen U.S. zoos, including San Francisco's, Chicago's and Detroit's have already shut down their elephant exhibits.
Game show host Bob Barker hopes this is just the start.
"I would personally like to see every zoo in the world closed," Barker told ABC News.
"Elephants have been exploited, they have been mistreated, they have been literally beaten and some of them killed," said Barker. "People want that changed."
Some elephants have developed joint and foot problems in zoos, where they spend all day on concrete floors.
Animal rights activists claim zoo enclosures are too small for the elephants to get proper exercise, and the resulting lack of activity, they say, leads the animals to become bored and lazy.
San Diego Zoo employees disagree with such claims, saying zoos can provide a suitable environment.
"It truly is not the size of the habitat," said Randy Rieches, a curator of mammals at the San Diego Wild Animal Park. "It's what you do for those animals within that habitat."
He said he also recognizes that mental stimulation is just as important as the space the elephants occupy.
"They're very intelligent creatures," said Rieches. "They cannot just languish in an exhibit. They must be given things to do."
The Wild Animal Park is making its elephants more active by giving them toys to play with, and letting them forage for hidden food. The elephants also spend minimal time standing on hard surfaces.
With the development of such programs, Rieches believes that the zoo elephants' quality of life is comparable to that of their counterparts in the wild.
"An elephant in the wild walks a larger distance not because he wants to, not because it's fun for them, but [because] they are foraging for food and for water," he said.
Many zoos strive to make conditions the best they can. At the Alaska Zoo in Anchorage, improvements were recently made to its elephant habitat, including the construction of a $100,000 treadmill for the zoo's lone pachyderm.
State Assemblyman Lloyd Levine, D-Calif., believes other zoos should follow this example. He unsuccessfully introduced a bill in the California Legislature this session that would have increased the minimum space requirement for zoo elephant habitats.
"Most zoos do an excellent job, but there are some zoos … that really need to do a much better job in their care of elephants," Levine said.
But for some, that is just not enough. Critics argue that zoo elephants should be moved to sanctuaries, where they can have more space and conditions that more closely mimic their natural habitat.
At the moment, such a move would prevent most Americans from seeing these animals up close.
The two elephant sanctuaries in the United States are not open to the public, and with a trip to elephant habitats in Asia or Africa out of the financial reach of most, that would mean elephants would be seen only in books and movies.
For now, providing a good environment for elephants remains the main priority at the Los Angeles Zoo.
This spring the Los Angeles City Council approved the construction of a $39 million, 3.5-acre exhibit that will house the zoo's two surviving elephants.