Each year the Zoological Society of London (ZSL) performs an animal weigh in at London Zoo. The height and mass of every animal, of which there are over 19,000, is recorded and submitted to the Zoological Information Management System.
Here we take a look at some of the more notable weigh-ins.
Above, Kumbuka, a Silverback Western Lowland Gorilla, came in at 7 feet.
An African Land snail tops the scale at just shy of 17 ounces (480 grams).
Zoo keepers measure a 6-foot llama, who mugs for the camera.
Zookeeper Nathan Coles weighs and measures an Eagle Owl named Max, who weighs just over 4 pounds (1.9 kilograms).
A Red Ruffed Lemur shows interest in the scales. Keepers at the world's oldest scientific zoo spend hours each year dutifully noting down the vital statistics of the creatures in their care.
A 7-week-old Philippine crocodile doesn't seem to mind taking its turn at the annual weigh in.
A mossy frog, weighing just shy of 1 1/2 ounces (37.1 grams), lays on a scale during the annual event.