A zookeeper poses for the media with two Bactrian camels during a photocall to publicise the annual stock-take at London Zoo in London, Thursday, Jan. 3, 2019. [Photo: AP]"

A zookeeper poses with Humboldt penguins during a photocall to publicise the annual stock-take at London Zoo in London, Thursday, Jan. 3, 2019. [Photo: AP]"

Jae Jae the Sumatran tiger stands near a sign during a photocall to publicise the annual stock-take at London Zoo in London, Thursday, Jan. 3, 2019. [Photo: AP]"