Photos: London Zoo's animals, from tarantulas to tigers, get their annual weigh-in

London: Staff at London Zoo got the measure of giant gorillas, plump penguins and skinny stick insects at the zoo’s annual animal weigh-in on Thursday.

Zookeepers tempted squirrel monkeys (above) onto scales, totted up tarantulas and used a curry-scented measuring stick to coax Sumatran tigers to stretch out.

A keeper measures a Tirachoidea stick insect. | Staff at the zoo, which is home to some 14,000 animals, will take several days to weigh and measure every mammal, bird, reptile, fish and invertebrate in its care.

A Mexican redknee trantula is placed on scales. | The results go into a database that is shared with zoos around the world.

Frank the Meerkat is weighed. | Angela Ryan, head of zoological operations at London Zoo, said an animal’s weight is vital information that can reveal whether creatures are healthy, and even which are pregnant.

“We have critically endangered animals here,” she said. “It’s absolutely vital that we are managing them, managing their health, that we’re breeding them and breeding them well and we’re having healthy offspring that can breed on again.”

An Asian Small Clawed Otter yawns during London Zoo's Annual Weigh In.

A Squirrel monkey is weighed and has their microchip scanned.