There are a few new arrivals to count in this year, including baby Asian rhino Bali and hundreds of butterflies in the zoo’s new tropical butterfly house.
The stocktake is compulsory as part of the zoo’s licence.
Keepers have the challenge of counting everything from curious squirrel monkeys to speedy cheetahs.
The zoo’s much-loved black-footed and rockhopper penguins will be counted alongside rarer species such as the scimitar-horned oryx – an extinct-in-the-wild antelope that Whipsnade Zoo, and others around the world, are breeding and reintroducing to their native habitat.
All of the information will be logged into the International Species Information System where it is used to manage the international breeding programmes for endangered animals.
Whipsnade is the UK’s largest zoo and home to more than 2,500 animals.