Inside, mercifully unharmed despite the lack of ventilation holes, was Isaac, a 32-year-old ring-tailed lemur, believed to be the oldest of its kind in North American captivity.

Someone had broken into the local public zoo overnight and cut holes in the enclosures housing lemurs and capuchin monkeys. While staff had quickly recaptured most of the primates (“They’re pretty easy to round up; they follow grapes,” noted zoo manager Ethan Fisher), the geriatric lemur was missing.

The mystery of Isaac’s wild night out was solved Monday, when federal prosecutors in Southern California announced that they had reached a plea agreement with a 19-year-old Newport Beach teenager for one misdemeanour count of unlawfully taking an endangered species.

Aquinas Kasbar broke into the Santa Ana zoo after closing and used bolt cutters to create a hole in the lemur and capuchin monkey enclosure, according to the plea agreement.

“Defendant knew that it was a lemur and wanted to keep it as a pet,” the plea agreement states.

Kasbar appears to have had a fairly quick change of heart, leaving Isaac at the hotel, not far from the zoo, later that same night.

He is expected to appear in court on May 28, and is facing a maximum penalty of one year in federal prison and a US$100,000 fine.

“Isaac is safe and sound,” confirmed Ciaran McEvoy, a spokesman for the US Attorney’s Office.

“It’s nice to have a little closure and know what happened,” Fisher said.

“Isaac is doing very well, and seems to be adjusting like a normal lemur would.”

Isaac was born in captivity and has lived at the Santa Ana zoo since 2001, Fisher said. He has one offspring, Dottie.

It was likely Isaac’s advanced age that enabled his capture, said Charles Welch, conservation coordinator for the Duke Lemur Centre.

“In general it would be very, very difficult to catch,” Welch said.

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“If you grab a lemur by the body, you’re very likely to get sliced to shreds or bitten. They’re not docile animals.”

Ring-tailed lemurs are among the most recognisable of the lemurs, a type of primate that is endemic solely to the island of Madagascar. ]

While ring-tailed lemurs are relatively common in captivity, they are critically endangered in the wild. A scientific study published in 2017 found that the species had fallen by 95 per cent since 2000, to an island-wide population of just 2,000 to 2,400 animals, though Welch cautioned that the study has been disputed.

Still, the species is facing severe challenges in the wild, due to habitat loss, hunting and the illegal pet trade.

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Welch said that during a 15-year stretch working at a conservation centre in Madagascar, he frequently encountered lemurs that had been taken as babies to be pets, only to “start biting people” as adults.

“People would bring them to the conservation centreand we would end up with a lot of aggressive lemurs there,” he said.

“They do not make good pets. We strongly discourage people from having them as pets.”