Photos: Polish zoo celebrates birth of critically endangered Sumatran tigers

A Polish zoo is celebrating the birth of four bright-eyed Sumatran tiger cubs in what’s being hailed as "a breeding success on a global scale."

Zoo officials announced their birth Friday, nearly two months after they were born on July 22. They wanted to make sure the cubs survived and could be vaccinated before their public debut, zoo spokesperson Weronika Łysek told The Associated Press.

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Sumatran tigers — the most critically endangered tiger subspecies — are under increasing pressure due to poaching and a shrinking jungle habitat. There are only about 400 of them left in the wild. The Wroclaw Zoo where the cubs were born has been breeding Sumatran tigers since the 1960s.

"The joy is even greater that all four tigers are developing healthily, are active, eager to eat and play with each other and with their parents," said Sergiusz Kmiecik, acting president of the zoo.

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The cubs weighed about 18 pounds as of Friday, roughly double the size of a domestic cat. Three of the cubs are males, which will help to balance the female-dominated Sumatran tiger populations in European zoos.

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The zoo is considering letting the zoo’s visitors and fans play a role in naming the four majestic cubs. They still have some growing to do before zoo officials decide where to send them.