London Zoo begins its annual animal weigh-in

It's that time of year again, when keepers at London Zoo weigh and measure hundreds of animals as part of a yearly check-up.

All of the animals' measurements are recorded in a database called the Zoological Information Management System.

It helps zookeepers all over the planet compare important information on thousands of endangered species.

But with so many animals, it's not always an easy task to carry out! Let's take a closer look at how it all went.

Every mammal, bird, reptile, fish and invertebrate across the zoo is weighed and measured. This capybara needed some tasty treats to be convinced to step onto the scales!

These cheeky Humboldt penguins couldn't wait to get on the scales! The penguins are native to the rocky coastal shores of Peru and Chile in South America and are listed as vulnerable to extinction by the International Union for the Conservation of Nature (IUCN).

Normal kitchen weighing scale were used to measure this giant hooded katydid. Did you know these impressive insects are not only known for their large size - but they are also able to camouflage themselves as leaves, which helps them hide from potential predators.

Animals of all ages and sizes were measured. Priscilla is London Zoo's 30-year-old giant Galapagos tortoise. They are the largest living species of tortoise in the world, and can weigh more than 400kg and survive without food or water for over a year!

London Zoo's animals, such as this Vietnamese land snail, are weighed and measured on a regular basis. This helps keepers monitor their health, wellbeing and development.

And finally, check out these playful ring-tailed lemurs who look like they're enjoying the attention and having a lot of fun! These primates live in troops of up to 30 individuals and are known for being very social and vocal animals.