An Argentinian court has decided that a Sumatran orangutan (Pongo abelii) named Sandra is a non-human person with rights, and will no longer be held captive in the Buenos Aires zoo where she has lived for the last 20 years. Sandra's case was taken up in November 2013 by the Association of Professional Lawyers for Animal Rights (AFADA). The lawyers argued that Sandra was intelligent and self-aware enough to understand and be negatively affected by her conditions, as well as being aware of the passage of time. The court agreed, and the judges unanimously voted in favor of a writ of habeas corpus for Sandra, deciding that she had been wrongfully imprisoned.

A writ of habeas corpus essentially states that the court must decide if the entity holding the person (in this case, the zookeepers, but more generally applies to prison officials) has adequate authority and grounds for keeping the person confined. While there is no doubt that the zoo has been holding Sandra captive for all of this time, the court had to decide if Sandra qualified as a non-human person, based on her level of intelligence.

Sandra was born nearly 29 years ago at a zoo in Berlin, Germany. For the last two decades, she has resided at the zoo in Buenos Aires. This lifetime of captivity is now coming to an end, as the court has decided she is free to leave the zoo and be relocated to a Brazilian wildlife sanctuary that will more accurately reflect the natural habitat of Sumatran orangutans.

The zoo has ten working days to appeal the court's decision. Adrian Sestelo, head of biology at the zoo, expressed his disagreement with the decision to the Argentinian newspaper La Nacion. He stated that Sumatran orangutans lived alone most of the time, and group interaction primarily occurred for mating and child-rearing purposes. Therefore, Sandra living alone was not tantamount to inhumane solitary confinement.

"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 humanize animal behavior," Sestelo said.

Though Sandra's case was successful in Argentina, similar cases in the United States have not been. Most recently, a NY court decided that a chimpanzee named Tommy who is privately owned did not qualify for legal personhood, and dismissed the case of habeas corpus that had been filed on his behalf. Even if the court had sided with Tommy, it legally would have just allowed him slightly more liberty beyond existing animal cruelty laws; it would not have made him a human person in the eyes of the court with all of the rights and responsibilities that accompany such a title.

However, the AFADA may be encouraged by Sandra's results to seek habeas corpus for other great apes as well as other animals held in zoos, circuses, and scientific laboratories. Similar animal rights groups, such as People for the Ethical Treatment of Animals, have been trying in vain to achieve the same goal, with very limited results.