London Zoo

London Zoo annual weigh-in...A llama gets measured gets weighed at the annual London Zoo weigh-in where animals are weighed and measured. PRESS ASSOCIATION Photo. Picture date: Thursday August 21, 2014. Photo credit should read: Philip Toscano/PA Wire

Philip Toscano/PA

A llama gets measured and weighed at the annual London Zoo weigh-in. 

Hand-painted models depicting a lion's head, pose for the photographers during a photo-op in central London's Carnaby Street, Tuesday, June 3, 2014. It was part of events marking the opening of the Zoological Society of London(London Zoo) first ever pop-up shop on the famous street, part of the Lions400 campaign to expose the plight of the endangered Asian lion.

Lefteris Pitarakis/AP

Hand-painted models depicting a lion’s head pose in central London’s Carnaby Street. It was part of events marking the opening of the Zoological Society of London’s first ever pop-up shop on the famous street, part of the Lions400 campaign to expose the plight of the endangered Asian lion

Zookeeper, Carl Ashworth, counts the number of penguins in his enclosure during London Zoo's annual stocktake.

Charlie Bibby/FT

Zookeeper Carl Ashworth counts the number of penguins in his enclosure during London Zoo’s annual stock take

An African bullfrog is weighed on a scale during a photocall to publicize the annual measuring of all the animals at the London Zoo.

Suzanne Plunkett /Reuters

An African bullfrog is weighed on a scale during a photocall to publicize the annual measuring of all the animals at the London Zoo.