Annual stocktake at London Zoo

The yearly stocktake, which lasts about a week, is required by the zoo's licence and involves counting the number of large and small animals that live there. The data is shared with other zoos via a database and is used to help manage the count of endangered species.

Zookeeper Mick Tiley poses for a photograph with Bactrian camels during the annual stocktake at ZSL London Zoo in London, Britain. (Photo: John Sibley/REUTERS)

Arya, an Asiatic lioness, during the annual stocktake. (Photo: John Sibley/REUTERS)

Zookeeper Hattie Sire poses with Humboldt penguins during the annual stocktake. (Photo: John Sibley/REUTERS)

Asiatic lions Bhanu and Arya. (Photo: John Sibley/REUTERS)

A squirrel monkey climbs on an abacus. (Photo: John Sibley/REUTERS)

Bhanu, an Asiatic lion, rubs his head. (Photo: John Sibley/REUTERS)

Squirrel monkeys climb on an abacus. (Photo: John Sibley/REUTERS)

Bhanu at the annual stocktake. (Photo: John Sibley/REUTERS)

Zookeeper Hattie Sire with Humboldt penguins. (Photo: John Sibley/REUTERS)

The tail of an Asiatic lion. (Photo: John Sibley/REUTERS)