No weigh! 10,000 animals get their turn on the London Zoo's hidden scales for annual check up

Published: 00:21, 25 August 2026 | Updated: 00:23, 25 August 2026 Penguins, capybaras, squirrel monkeys and a Vietnamese magnolia snail were among 10,000 residents of London Zoo measured in the annual 'weigh-in' on Monday. Animals were enticed, led or coaxed onto the scales, as keepers ensured that every mammal, bird, reptile, fish and invertebrate was weighed and recorded. Some animals are trained to step on the scales while devices for birds are hidden in doorways. A Bolivian black-capped squirrel monkey was placed on a perch for the weigh-in while brother and sister capybaras Gizmo and Kiwi were lured onto the scales with food. The park's Bolivian squirrel monkeys were also led onto the scales disguised as a climbing frame. Meanwhile, the inquisitive Humboldt penguins were enticed with the prospect of fish, before being allowed back to their usual playtime. There are more than 10,000 animals at the zoo across 4,000 species. The zoo's smallest animals are Partula snails, which weigh less than one gram. The inquistive Humboldt penguins had their weight taken as they inspected the scales during the annual weigh-in at ZSL London Zoo in London A zookeeper weighs the Giant Vietnamese Magnolia Snails One of the zoos resident capybaras appeared less then pleased to join in with the weigh-in A katydid, known as bush criket, is weighed on top of a rock at the zoo Zoo keeper Mick strokes Capybara Gizmo as he gets his measurements taken Zoo keeper Rowan got creative to try and tempt one of the Bolivian squairrel monkeys into being weighed Humbolt Penguins are tempted on to the scales by fish from a keeper and then get a chance to return to play A pair of penguins are lured onto the scales with the offer of a fish snack Kiwi the capybara was lured towards his scales with the offer of food A pair of squirrel monkeys perch on a podium as they are unwittingly weighed A zookeeper holds the katydids on its rock as it is weighed at the London Zoo A monkey watches over its keeper as he tries to take measurements A pair of capybaras take their turns on the scales at London Zoo Animals at London Zoo are regularly weighed and measured to monitor health, development and identify pregnancies. Measurements are added to an information system shared with conservationists across the world to provide information 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.' The Zoological Society of London, which runs the zoo, celebrated its 200th anniversary this year.