London Zoo’s annual weigh-in 2026

Humboldt penguins are weighed during a photocall for the annual animal weigh-in at ZSL London Zoo, in London, Britain, 24 August 2026. According to the zoo, the animals are weighed and measured on a regular basis as way of continually monitoring their health, development and even identifying pregnancies, which the information is shared with other zoos to help manage worldwide conservation breeding programmes for endangered animals.