There's a reason animals in most zoos look so sad. Few zoos can even begin to meet animals' complex needs. Animals in zoos are denied everything that is natural and important to them, and they're confined to enclosures that are infinitely smaller than the open spaces they would inhabit in their real homes in the wild.

In 2004, zoologists at Oxford University confirmed what those of us who have paused to consider animals' plights have always known: Animals suffer in captivity. Polar bears, lions, tigers, elephants, cheetahs, and other animals who might roam hundreds of miles if their lives were uninterrupted by humans become neurotic in zoos. Their constant pacing, rocking, and self-mutilation are signs that they are deeply stressed and miserable.

Zoo defenders like to claim that these facilities serve some sort of noble conservation purpose. But the truth is that zoos serve merely to exploit exotic animals to draw visitors to the zoo, which saps funding from genuine preservation and conservation efforts. Zoos only teach people that it's acceptable to confine and deprive animals for the sake of entertainment.

Zoos know that nothing brings in paying visitors faster than newborn animals. But their greed-motivated breeding programs—which often operate under the guise of "species preservation"—lead to the problem of what to do with less crowd-pleasing adult animals. Zoos have solved that by routinely disrupting bonds and loving relationships among adult animals by trading away, lending out, selling off, bartering, and warehousing the animals that they no longer want.

PETA needs your help to expose the disgusting practices that are routine in these animal prisons. It is up to us to make sure that people know the misery that animals suffer in captivity so that people can make informed decisions. By donating online to PETA today, you'll help us put pressure on zoos to become honest sanctuaries or close down. You'll help us educate the ticket-buying public about why people who truly love animals shouldn't patronize zoos.

With your support, PETA will pressure the Association of Zoos and Aquariums (AZA) to pull its accreditation from zoos that engage in outright cruelty to animals. We recently discovered that the Dickerson Park Zoo in Springfield, Mo., has sold or "donated" a giraffe, a kudu, five kangaroos, and two deer to Buddy Jordan—a notorious animal dealer who sells animals to exotic-animal auctions and breeders, unaccredited zoos, and even hunting ranches.

Babies born at the zoo should not end up as trophies on a hunter's wall. By taking action today, you can help us pressure zoos everywhere to provide a safe environment for the animals entrusted to their care.

Sign the petition to the AZA and demand that it immediately yank the accreditation of the Dickerson Park Zoo for transferring animals to wildlife dealers and ranchers.