Five elderly African elephants at a Colorado zoo will stay there, after the US state’s highest court said the animals had no legal right to demand their release because they are not human.

Tuesday’s 6-0 decision by Colorado’s Supreme Court means Jambo, Kimba, LouLou, Lucky and Missy will remain at the Cheyenne Mountain Zoo in Colorado Springs.

It followed a similar decision in 2022 by New York state’s highest court, the Court of Appeals, that another aged elephant, Happy, had to remain at New York City’s Bronx Zoo.

Animal rights non-profit Nonhuman Rights Project brought both cases on the elephants’ behalf under a legal doctrine known as “habeas corpus”, saying the animals should live in sanctuaries.

Citing affidavits from seven animal biologists, the group told the Colorado court that elephants are highly social and mobile, share many cognitive abilities with humans including empathy and self-awareness, and when confined in zoos can experience boredom and stress that could lead to brain damage.

But the court said Colorado’s habeas statute applied to persons, not to non-human animals, “no matter how cognitively, psychologically, or socially sophisticated” they might be.

It also said Nonhuman Rights Project’s concession during oral argument that it was seeking only different confinement, not complete freedom, for the elephants was another reason to treat them and humans differently.

The case “does not turn on our regard for these majestic animals generally or these five elephants specifically”, Justice Maria Berkenkotter wrote.

“Because an elephant is not a person, the elephants here do not have standing to bring a habeas corpus claim.”

In a statement, Nonhuman Rights Project said the decision “perpetuates a clear injustice” that consigns the five elephants to “a lifetime of mental and physical suffering”. It has not determined its next legal steps.

The zoo welcomed the outcome in a separate statement, but expressed disappointment at having spent 19 months defending against a “frivolous” case that the animal rights group has pursued unsuccessfully against several other reputable zoos.

“We’ve wasted valuable time and money responding to them in courts and in the court of public opinion,” the zoo said.

In Tuesday’s decision, Berkenkotter also emphasised that legislators, not judges, were best positioned to expand legal rights of non-human animals.

She said counting those animals as persons would be a “monumental change” that one would expect legislators to make explicit if they really meant it.

-AAP