From the minute to the massive, more than 17,000 animals at London Zoo have been weighed and measured to keep the zoo's database up to date.
The annual weigh-in kept zookeepers busy, jotting down the vital statistics of everything including penguins, monkeys, frogs, owls and tortoises, as a way of keeping track of their health and wellbeing.
Each measurement is recorded and shared with zoos around the world, helping zookeepers compare notes on thousands of endangered species.
With all their different demeanours and personalities, staff had to sometimes use a few tricks to get the animals onto the scales and in front of the measuring tape.
To get the penguins to stand up and be counted, they walked over scales to get to their morning feed; tortoises were trained to stand on the scales hidden in grass.
As well as getting a feel for the general wellbeing, it's also an opportunity for zookeepers to identify potentially pregnant animals.