For the first time anywhere, an ape has received the same basic rights as her human captors. The female orangutan, whose home is the Buenos Aires Zoo, was the beneficiary on December 18 of the decision by a high-level Argentine criminal appeals court.

The ruling will change forever the life of this hybrid of two orangutan species—one from Borneo, the other from Sumatra—and may ultimately spur the nascent movement to set free other animals living in captivity.

In Argentina, at least, Sandra now has the right to life, liberty and freedom from harm. “The ruling was historic because before a nonhuman primate like Sandra was considered an object and therefore there was no dispute about its captivity, says Andrés Gil Dominguez  of the Association of Professional Lawyers for Animal Rights in Argentina, which filed a habeas corpus petition for Sandra, asserting that she had been unjustifably denied her freedom.”

The court’s decision will lead to another proceeding on the orangutan’s behalf to find a home outside the zoo’s cages where Sandra, born in captivity in Germany in 1986, has lived for the last 20 years. The Argentine justice system will now convene a committee of experts to find a sanctuary or another home for Sandra, as long as the aging orang is healthy enough to travel elsewhere.

Sandra’s case began when a nongovernmental organization filed for her habeas corpusin November, an unsuccessful petition that was later heard by the appeals court. Interest in procuring the orang’s freedom dates back to 2012 when a previous administration at the Buenos Aires Zoo, led by zoologist Claudio Bertonatti, had considered the possibility of sending the ape to a sanctuary but never took any action.

Sandra’s case will likely energize other legal efforts for other animals—in particular, 17 chimpanzees in zoos throughout Argentina.  “Considering that they are very close to human primates, it is an absurdity that they are still in captivity in prison," says primatologist Aldo Giúdice of the University of Buenos Aires.

Before Sandra’s case other legal claims were filed for zoo primates in the Argentine provinces of Córdoba, Río Negro, Santiago del Estero and Entre Rios. Outside of Argentina there was a case in 2005 for a chimpanzee, Suiça, in the zoo in San Salvador, Brazil, but the animal died before the case could be adjudicated. In 2012 People for the Ethical Treatment of Animals (PETA) was unsuccessful in invoking the U.S. Constitution’s 13th Amendment abolishing slavery and involutnary servitude to gain freedom for orcas in captivity.

In 2013 the Nonhuman Rights Project initiated three legal claims on behalf of four chimpanzees in New York State. Initially rejected, the cases are in the midst of appeals. "With our claims, we are looking for imprisoned nonhuman animals to be returned to their natural environment,” says Steven Wise, president of the organization, which counts renowned British primatologist Jane Goodall as a member. “If that’s not possible, we will try to send them to a suitable sanctuary.

The groundswell of support for freeing animals grows out of 40 years of primate research. "Studies such as those by Dian Fossey, Jane Goodall and other scientists helped to position the great apes as people,” Giúdice says. "Seeing them in zoos today recalls human exhibits from other regions of the world in the World’s Fairs in Paris in the 19th century.”

“Scientific research,” he adds, “has shown that they are sentient beings with reason, self-consciousness and individuality. We cannot be accomplices and let them suffer in prison.”