A white-backed vulture at the Dallas Zoo has died under “unusual” circumstances. Zookeepers called in the Dallas Police Department to investigate the loss of the endangered bird. And are still looking into other recent “strange events.”

Saturday the Dallas Zoo posted on Twitter that "This weekend, our staff found that one of the endangered vultures in our Wilds of Africa habitats had died. The animal care team is heartbroken over this tremendous loss." 

A series of posts explained that "The circumstances of the death are unusual, and the death does not appear to be from natural causes." 

"In the past week, we have added additional cameras throughout the Zoo and increased onsite security patrols during the overnight hours. We will continue to implement and expand our safety and security measures to whatever level necessary to keep our animals and staff safe."

The zoo did not give more specific details about the rare vulture's death, but from all indications, the bird was murdered. And they did say that the Dallas Police Department had been called in, again.

It was less than 2-weeks ago when Nova, the clouded leopard was intentionally let out of her habitat. The zoo was closed so she could be safely returned. And the hours-long search for her went viral.

Strange events at the zoo

Police are continuing to investigate a series of strange events at the Dallas Zoo.

Two weeks ago, a Code Blue warning went out when Nova escaped from her enclosure. The Police later said that the leopard’s habitat had a suspicious cut in the enclosure.

During the January 13 search for the clouded leopard, the zoo claimed she was not dangerous. And she was "bigger than a house cat and smaller than most bobcats."

Sgt. Warren Mitchell, a public information officer for the Dallas Police told the press while still searching for the clouded leopard that "after investigating, it is our belief that this was an intentional act."

During the investigation, it was discovered that there were similar cuts in the fenced enclosure area which held the langurs. But all of the langur monkeys were accounted for.

Langurs are rare African and Asian native monkeys.

In a follow-up statement, police explained "a cutting tool was intentionally used to cut an opening in the fencing of the Clouded Leopard's habitat." A "similar cut" had been made in the langurs' enclosure. And none of the monkeys had left their habitat.

Clouded leopards, langurs, and white-backed vultures are all extremely rare animals. And the zoo is saddened by the loss of the irreplaceable vulture.

The Dallas Zoo is the oldest operating zoo in Texas. And more than 400 species and 2,000 animals inhabit the historic place.

Police will now investigate the vulture’s death in the latest of the zoo’s strange events.