Orang-utan case latest in attempts to give Great Ape family human status — all of which have failed, until now.
The move to grant an orang-utan in Argentina some legal rights enjoyed by humans could open the floodgates to thousands of similar cases.
The decision clears the way for Sandra, a shy 29-year-old, to be freed from Buenos Aires Zoo after spending her entire life in captivity.
The ruling came after animal rights campaigners filed a habeas corpus petition on behalf of the Sumatran orang-utan, who was born at a German zoo and was transferred to Buenos Aires two decades ago.
The outcome hinged on whether Sandra should be treated as a "thing" or a "person", with the Association of Officials and Lawyers for Animal Rights (Afada) arguing that she should not be treated as an object because of her intelligence and complex ways of thinking. The court agreed Sandra deserved the basic rights of a "non-human person".
Andres Gil Dominguez, who represented the orang-utan, said: "It sets a precedent that changes the paradigm of animal guardianship and will impact their rights. ... It will lead to a lot of discussions. From this ruling forward ... the discussion will be whether captivity in itself damages their rights.
"This opens the way not only for other Great Apes, but also for other sentient beings which are unfairly and arbitrarily deprived of their liberty in zoos, circuses, water parks and scientific laboratories," Afada lawyer Paul Buompadre told Argentina's La Nacion newspaper.
Sandra will be transferred to a sanctuary in Brazil unless the zoo appeals within the next 10 days. The zoo was tight-lipped yesterday about its next move. However, its head of biology, Adrian Sestelo, indicated that he thought it inappropriate to compare the animal with a human.
"When you don't know the biology of a species, to unjustifiably claim it suffers abuse, is stressed or depressed, is to make one of man's most common mistakes, which is to humanise animal behaviour."
Sandra's case was the latest in a series that have attempted to give the non-human members of the Great Ape family human status - all of which have failed, until now.
Sandra's victory was an appeal against an earlier rejection, while a high-profile case in New York earlier this month dismissed Tommy the chimpanzee's quest for freedom.
In their ruling on the privately owned, retired entertainment chimp living in a cage in New York state, the judges said: "So far as legal theory is concerned, a person is any being whom the law regards as capable of rights and duties ... chimpanzees cannot bear any legal duties, submit to societal responsibilities or be held accountable for their actions."
The Nonhuman Rights Project, which brought the case, said it would appeal.
- Independent, AP