Sumatran Tiger Kirana just gave birth to two healthy cubs. View this video on YouTube The cubs appear from 0.30. It's the second litter for 7-year-old Kirani. Chester Zoo The gender of the cubs is not yet known. Chester Zoo There are only 400 Sumatran tigers left in the wild. Chester Zoo Kirana's first litter was born in 2011. Chester Zoo / Via zooborns.com The cubs were moved to another European zoo, "as part of a cooperative breeding program aimed at increasing genetic diversity among these endangered cats".