A white Bengal tiger cub plays with its mother in a zoo in the Siberian city of Novosibirsk, about 2,800 kilometers (1,750 miles) east of Moscow, Russia, Tuesday, April 21, 2015. Two blue-eyed Bengal tiger cubs were born in March to a couple of white tigers at Novosibirsk zoo. (Photo by Ilnar Salakhiev/AP Photo)

Chinese Panda Yang Guang arrives at Edinburgh Airport on December 4, 2011 in Edinburgh, Scotland. Tian Tian and Yang Guang, a pair of eight-year-old giant pandas arrived on a specially chartered flight and will be the first to live in the UK for 17 years. Edinburgh Zoo are hopeful that the pandas will give birth to cubs during their 10 year stay in Scotland. (Photo by Jeff J Mitchell/Getty Images)

Yuan Zi, a male giant panda and Huan Huan, a female giant panda, share their life inside their enclosure at Zoo Parc De Beauval on January 25, 2012 in Beauval, France. A pair of giant pandas which have been loaned to the zoo by China, where they hope the pair will reproduce and help boost the world's dwindling panda population. (Photo by Franck Prevel/Getty Images)

Actress Angelina Jolie (L) and actor Jack Black attend the “Kung Fu Panda 2” photocall during the 64th Annual Cannes Film Festival at the Carlton Hotel on May 12, 2011 in Cannes, France. (Photo by Vittorio Zunino Celotto/Getty Images)

A woman poses as she has her picture taken amid 1600 panda bear sculptures in Berlin August 5, 2013. Marking the 50th anniversary of its existence, on Monday the German branch of the World Wide Fund for Nature (WWF) environmental conservation organisation placed 1600 panda bear sculptures on front of Berlin's main train station to draw attention to the plight of the endangered species that serves as the NGO's mascot. There are currently 1600 panda bears alive in the wild, the organisation said in a press release. (Photo by Thomas Peter/Reuters)

Three-month old cheetah cubs make their public debut at the Smithsonian National Zoo on July 24, 2012 in Washington, DC. (Photo by T.J. Kirkpatrick)

Gaza authorities say two newborn lion cubs just unveiled by Hamas as prized additions in a zoo they run have died. Mohammad Abdel-Rahman, the acting manager of the Beit Lahiya zoo in northern Gaza, said Thursday the cubs died of an unspecified illness. He said the zoo's staff was unable to save them because they lacked experience in caring for newborn cubs. Photo: Two-day-old lion cubs Fajr and Sjel are fed at a zoo in the northern Gaza Strip town of Beit Lahia, on November 19, 2013. (Photo by Mohammed Abed/AFP Photo)