Keeper Jack Sargent measures Perry, a 6-foot llama, during the annual weigh-in at ZSL London Zoo on Aug. 21, 2014 in London, England. The height and mass of every animal in the zoo, of which there are over 16,000, is recorded and submitted to the Zoological Information Management System. This is combined with animal measurement data collected from over 800 zoos and aquariums in almost 80 countries, from which zoologists can compare information on thousands of endangered species.
Kumbuka, a Silverback Western Lowland Gorilla, is measured at 7 feet during the annual weigh on Aug. 21.
A "jungle nymph" is measured during the annual weigh-in at the London Zoo.
A keeper weighs a mossy frog in a weighing spoon during the annual weigh-in at ZSL London Zoo.
A squirrel monkey grabs food left on scales by a zookeeper during the annual weigh-in.
Zookeeper Dave Clarke poses with one of the world's smallest and rarest snails, a Partula Snail, while weighing one of the largest in the world, an African Land Snail, at London Zoo on Aug. 21.
Max the owl is weighed.
Perry the llama is measured at the London Zoo on Aug. 21.