The month-old Siberian tiger quadruplets stay at Hengdaohezi Feline Breeding Center in Hailin, northeast China's Heilongjiang Province, April 20, 2019. More than 20 cubs have been born so far this year at the world's largest Siberian tiger breeding center in northeast China's Heilongjiang Province. The China Hengdaohezi Feline Breeding Center is expected to welcome around 100 cubs by the end of this year, according to the center. Most of the cubs were born from March to June, said Qiu Hongkun, a senior official with the center. (Xinhua/Zhang Chunxiang)