Rowan Swainson weighs a Bolivian black-capped squirrel monkey.

Monkeys, penguins and even snails stepped onto the scales.

A pair of capybara siblings and a giant magnolia land snail were among the incredible species that stepped (or slithered!) onto the scales for London Zoo’s annual weigh-in.

The event, which took place on Monday (24 August), forms part of vital global conservation efforts and ensures key health information for each animal is accurate and up to date.

Capybaras Kiwi and Gizmo weighed-in at 45kg and 50.5kg, respectively, while the land snail tipped the scales at a modest 102.5g. All recorded data is added to the Zoological Information Management System (Species360) database, shared with conservationists around the world. 

Daniel Simmonds, London Zoo’s animal operations manager, said: “Regular weigh-ins help zookeepers track the health of our animals, including invertebrates 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.”

ZSL London Zoo cares for a wide array of species, from powerful Sumatran tigers to miniscule Partula snails. To ensure animals willingly partake in the weigh-ins, keepers devise creative solutions, such as disguising scales in doorways or encouraging birds onto perch scales. 

Daniel added: “For 200 years, ZSL has been at the forefront of animal care and veterinary innovation, and the wildlife health centre is the next chapter in that story. While visitors will be able to see our vets and scientists at work, the impact will extend far beyond London. 

“The centre will support ZSL’s pioneering research into wildlife health, helping us better understand the threats facing animals around the world and contributing to conservation efforts that protect species for generations to come. It's a powerful example of how London Zoo combines unforgettable animal experiences with conservation and science on a global scale."

Image (C) ZSL London.