Mystery at the Dallas Zoo: 2 monkeys are missing, believed to have been taken, following a leopard escape, a dead vulture, and 'suspicious' rips in enclosures

• Two tamarin monkeys are missing from the Dallas Zoo and police believe they were "intentionally taken."
• Earlier this month, a clouded leopard was missing for several hours and an endangered vulture died.

Two emperor tamarin monkeys are missing and are believed to have been "intentionally taken" from the Dallas Zoo, marking the latest mystery involving the zoo's animals this month.

When Dallas Zoo employees discovered the monkeys were missing on Monday morning, it was "clear the habitat had been intentionally compromised," the zoo said in a statement provided to Insider. The zoo contacted the Dallas Police Department, which is investigating the incident.

DPD confirmed to Insider that their preliminary investigation determined an "intentional cut" was made in the monkeys' habitat: "Two monkeys are missing, and it is believed the animals were intentionally taken from the enclosure."

The emperor tamarin monkeys, a small species native to South America, "would likely stay close to home," the zoo said in a statement, adding the habitat and zoo grounds had been searched but the monkeys had not yet been located.

The missing monkeys come after a series of strange occurrences at the zoo.

On January 13, a clouded leopard named Nova was missing for several hours before being located on the zoo grounds. Police believe someone had intentionally cut the leopard's habitat and that a similarly "suspicious" tear was made in an enclosure containing langurs, a type of monkey native to Africa and Asia, but that all the monkeys were accounted for.

About a week later, an endangered vulture at the zoo died under "unusual" circumstances.

The incidents weren't the only unusual events to unfold at a US zoo this month.

In Louisiana, at least 12 squirrel monkeys were stolen from a zoo over the weekend. Zoosiana, located in Broussard, said someone broke into the facility shortly before midnight on Saturday.

"The individual targeted facilities of smaller primates and specifically compromised the Squirrel Monkey exhibit. The individual was unfortunately successful in stealing at least 12 squirrel monkeys," Zoosiana said on its Facebook page, adding police were investigating the incident.

Zooisiana is located about 400 miles, or six hours driving, from the Dallas Zoo. Police have given no indication that the incidents are believed to be connected.

A longtime professional zoo keeper told Insider was puzzled by the incidents.

"The coincidence is a little difficult to ignore," Ed Hansen, the CEO of the American Association of Zoo Keepers, told Insider. "Folks don't wander into zoos and start cutting enclosures apart to either steal animals or see what happens when they get loose. That takes a pretty strange mind."

Hansen, who spent 25 years at Reid Park Zoo in Tucson, Arizona, said he'd heard of many incidents over the years of people disrupting zoo enclosures or stealing animals. Still, he said it wasn't an incredibly common occurrence and that for it to happen around the same time at two separate zoos was "very unusual."

As for the series of incidents at the Dallas Zoo, he said he'd never heard of something like that happening.

Hansen said it's possible the people stealing the monkeys are interested in keeping them as pets or in selling them, but that they'd be unlikely to succeed at either. Though the monkeys may be small enough to keep in a cage at home, they require a specialized diet. "If they don't know how to care for them, they're going to get sick and die," he said.

The monkeys would also be difficult to sell, especially without detection from law enforcement, he added.

"That's not something you're going to stick on Craigslist."

Have a news tip? Contact this reporter at kvlamis@insider.com.