Keepers at London Zoo weighed and measured around 10,000 animals on Monday as part of the zoo's annual weigh-in, with penguins, capybaras, squirrel monkeys and a Vietnamese magnolia snail among those enticed, led or coaxed onto the scales.
Every mammal, bird, reptile, fish and invertebrate at the zoo was weighed and recorded during the exercise. Some animals are trained to walk onto scales themselves, while weighing devices for birds are hidden inside doorways so they can be measured without noticing.
The zoo's Humboldt penguins were enticed onto the scales with the promise of fish, before being allowed back to their usual playtime.
Among the smaller residents to be checked were the zoo's giant Vietnamese magnolia snails, weighed individually by keepers.
Capybaras and squirrel monkeys take their turn
Brother and sister capybaras Gizmo and Kiwi were lured onto the scales with food. A Bolivian black-capped squirrel monkey was placed on a perch for its weigh-in, while other squirrel monkeys at the zoo were led onto the scales disguised as a climbing frame.
A katydid, also known as a bush cricket, was weighed on top of a rock.
Zookeeper Mick was pictured stroking Gizmo the capybara as his measurements were taken.
Zookeeper Rowan got creative in trying to tempt one of the Bolivian squirrel monkeys into being weighed.
Other Humboldt penguins were lured onto the scales in pairs with the offer of a fish snack.
Why London Zoo weighs its animals
There are more than 10,000 animals at London Zoo across some 4,000 species. Its smallest residents are Partula snails, which weigh less than one gram.
Animals at the zoo are regularly weighed and measured to monitor their health and development and to identify pregnancies. The measurements are added to an information system shared with conservationists around the world, providing data on endangered species.
London Zoo's animal operations manager, Daniel Simmonds, said: "Regular weigh-ins help zookeepers track the health of our animals, including insects like the magnolia land snails, the capybaras, and Humboldt penguins, and genuinely help us manage the care of these animals, who play a vital role in our global conservation efforts."
200 years of the Zoological Society of London
London Zoo is run by the Zoological Society of London (ZSL), a conservation charity that is celebrating its 200th anniversary this year. The zoo itself first opened its gates in 1828.
