Every creature in London Zoo, from giant mammals to tiny insects, is being counted as part of the zoo's annual census, which is currently underway, the BBC reported.
More than 850 species and thousands of individual animals have to be registered in the week-long stock-taking, which is required as part of the zoo's licensing agreement.
Some of the world's most endangered species are being counted for the first time, including the first spiny-headed lizards to be born in Britain.
Spectacled owls, oriental short-clawed otters, Humboldt penguins, jungle nymph insects and western lowland silverback gorillas are among the creatures being logged in the census.
The data is shared with other zoos worldwide via the International Species Information System to spread knowledge and help with breeding programs.
“All of the keeping staff at London Zoo are out with their animals and keeping an eye on how they have been over the last year,” said zoological manager Mark Habben.
“Any new births are recorded and we log all of that information so that it's accessible for other animal collections.
“2013 was a very successful year for us breeding-wise. We had our female tapir give birth so we have got a young tapir here on exhibit which is fantastic."
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