Tiger cubs Lenuta and her brother Costel sit outside their enclosure at Galati Zoo in Bucharest, Romania. The two tiger cubs belong to one of the world's most endangered species, the Siberian tiger.

The species, native to northern China, southern Russia and parts of North Korea is on the brink of extinction in the wild, decimated by poaching and loss of habitat. Scientists believe only a few hundred now live outside captivity.

(Bogdan Cristel/Reuters)