Siberian tigers socialize at a tiger park as snow falls in Hailin, northeast China's Heilongjiang Province, April 18, 2019. (Xinhua/Wang Jianwei)

　　Two Siberian tigers socialize with one another at a tiger park as snow falls in Hailin, northeast China's Heilongjiang Province, April 18, 2019. (Xinhua/Wang Jianwei)

　　Siberian tigers look around at a tiger park as snow falls in Hailin, northeast China's Heilongjiang Province, April 18, 2019. (Xinhua/Wang Jianwei)

　　A Siberian tiger looks around at a tiger park as snow falls in Hailin, northeast China's Heilongjiang Province, April 18, 2019. (Xinhua/Wang Jianwei)

　　A Siberian tiger yawns at a tiger park as snow falls in Hailin, northeast China's Heilongjiang Province, April 18, 2019. (Xinhua/Wang Jianwei)

　　Siberian tigers wander at a tiger park as snow falls in Hailin, northeast China's Heilongjiang Province, April 18, 2019. (Xinhua/Wang Jianwei)

　　Two Siberian tigers take a rest at a tiger park as snow falls in Hailin, northeast China's Heilongjiang Province, April 18, 2019. (Xinhua/Wang Jianwei)

　　A Siberian tiger takes a rest at a tiger park as snow falls in Hailin, northeast China's Heilongjiang Province, April 18, 2019. (Xinhua/Wang Jianwei)

　　A Siberian tiger takes a rest at a tiger park as snow falls in Hailin, northeast China's Heilongjiang Province, April 18, 2019. (Xinhua/Wang Jianwei)

　　Siberian tigers look around at a tiger park as snow falls in Hailin, northeast China's Heilongjiang Province, April 18, 2019. (Xinhua/Wang Jianwei)

　　Two Siberian tigers socialize with one another at a tiger park as snow falls in Hailin, northeast China's Heilongjiang Province, April 18, 2019. (Xinhua/Wang Jianwei)

　　Siberian tigers take a rest at a tiger park as snow falls in Hailin, northeast China's Heilongjiang Province, April 18, 2019. (Xinhua/Wang Jianwei)

　　Siberian tigers are seen at a tiger park as snow falls in Hailin, northeast China's Heilongjiang Province, April 18, 2019. (Xinhua/Wang Jianwei)