Two monkeys are believed to have been abducted from the Dallas Zoo after a series of strange incidents on the attraction.
Dallas police said no arrests were made in any of the investigations, including the cutting of the cages and the suspicious death of the endangered bird, and did not confirm if the incidents were linked.
In the latter case, officers believe, someone cut a hole in the enclosure and took away two emperor tamarin monkeys, small primates with long mustache-like whiskers.
“It was clear that the habitat had been deliberately disturbed,” the zoo said in a statement.
Earlier this month, the zoo closed for a day of searching when Clouded leopard named Nova is missing.
She was eventually found near her dwelling, but police said they cut a hole in her fence with a tool.
Please use Chrome browser for more accessible video player
A capuchin monkey was thought to be responsible for a mysterious phone call to the sheriff’s office last year.
A similar hole was found in a langur enclosure, but none of them got out.
A week later, an endangered vulture named Pin was found dead and the zoo said the death was not natural.
Gregg Hudson, the zoo’s chief executive, said the vulture had an injury.
Ed Hansen, executive director of the American Association of Zookeepers, said he couldn’t think of a zoo that had so many similar incidents so often.
“It looks like someone really has a problem with the Dallas Zoo,” he said.
Mr. Hansen described the Dallas Zoo’s reputation as “excellent” in the industry, adding that accredited zoos have double perimeter fencing and that a zoo as large as Dallas should have a security patrol.
The Dallas Zoo said in a statement that it has added additional cameras and increased night patrols.
It also states that the two missing emperor tamarins are likely to remain close to their habitat, but a search within the zoo has yielded no results.
Animals have previously escaped from Dallas Zoo enclosures: Jabari, a 340-pound (154 kg) gorilla, jumped over a wall in 2004.
He staged a 40-minute rampage that wounded three people, after which he was shot dead by the police.
