Every year, the London Zoo conducts a health check on its animals, and no creature - no matter how big or small - is exempt.

Not even the Iberian midwife toad (above), which grows to a length of only about 4cm.

The toad is actually a species of frog in the Alytidae family, and is found in Portugal and western Spain.

This species is unusual in that the male provides most of the parental care. The males carry a string of fertilised eggs with them, hence the name "midwife".

At the annual check-up, held last Wednesday, more than 17,000 animals had their weight and other measurements recorded.

The exercise is carried out on a regular basis by the zookeepers as a way of keeping track of every animal's health and well-being.

According to the zoo's Twitter account, it can also be helpful for simple things such as medicine dosage.

The London Zoo's findings are then shared with zoos all over the world to help them keep an eye on endangered species.

This year's event was quite the scene with camels, Humboldt penguins, tamarin monkeys, eagle owls and giant tortoises all participating.