Elephants have the biggest brain of any land mammal, and we believe them to be some of the most intelligent and social animals aside from humans. But should they have some of the same rights as humans? An animal rights group, the Nonhuman Rights Project (NhRP), recently filed a lawsuit arguing just that.

The NhRP is using the common law legal precedent of habeas corpus, which has been used for centuries to seek relief for people who have been held captive against their will. But this is the first-ever petition for a writ of habeas corpus on behalf of captive elephants.

"Our clients are Beulah, Karen, and Minnie, used for decades in traveling circuses and fairs and currently held in captivity by Connecticut’s Commerford Zoo," according to the NhRP blog. "We are asking Connecticut common law courts to recognize Beulah, Karen and Minnie’s nonhuman legal personhood and fundamental right to bodily liberty as self-aware, autonomous beings and, as such, order them immediately released to an appropriate sanctuary."

The Performing Animal Welfare Society (PAWS) in California has agreed to take the elephants, the group says.

Personhood for chimpanzees?

chimp at the Leipzig Zoo A chimp lounges in an enclosure at the Leipzig Zoo in Leipzig, Germany. (Photo: Henner Damke/Shutterstock)

Chimpanzees and humans share about 99 percent of the same DNA. Does that mean they should have the same rights as people?

In 2013, the NhRP filed a similar lawsuit on behalf of Tommy, a captive chimpanzee that lives in a shed behind a used-car lot in Gloversville, N.Y. The lawsuit, filed in New York State Supreme Court, demanded that Tommy be recognized as a legal person who has a right to liberty.

In Tommy's case, and in the case of the elephants, "liberty" means removing captive animals from owners and relocating to an animal sanctuary "where they can live out the rest of their days with others of their kind in an environment as close to the wild as is possible in North America," according to the group.

According to the NhRP, there used to be six chimpanzees at the Gloversville business, which also rented reindeer for Christmas shows. Tommy is the only one still living, and the organization was "deeply concerned that Tommy, too, could die at any time before he could ever had a chance to walk on grass and climb in trees with others of his own kind."

Patrick Lavery, the owner of the facility, told the New York Times that Tommy lives in a large cage with lots of toys, which is much better than where the chimp previously lived.

"If they were to see where this chimp lived for the first 30 years of his life, they would jump up and down for joy about where he is now," he said. Lavery said he complies with all regulations regarding owning the chimpanzee and has been trying to find a sanctuary to take him. He said the facilities he has approached are all full and don't have room for Tommy.

A judge ruled against the lawsuit, and the NhRP appealed, but in June 2017 the appeals court unanimously upheld the lower court's ruling.

Editor's note: This story has been updated since it was originally published in December 2013.