In pictures: London Zoo animals counted for stocktake
Tigers, penguins and a lesser-known aye-aye baby were some of the animals counted by zookeepers at London Zoo's annual stock count.
Sumatran Tiger cubs were just one of the hundreds of species counted. These two pictured, Achilles and Karis, arrived at the zoo in 2016.
In previous years, the count has taken about a week to complete.
Genghis, a Bactrian camel, was also counted.
Although it is undertaken once a year, keepers have an inventory which is updated continuously. The count is required as part of the zoo's licence.
Last year, nearly 18,500 animals were counted, including 21 red-kneed spiders and six Philippine crocodiles. There were a total of 712 species.
The results are logged into the International Species Information System (ISIS) where the data is then shared with other zoos.
Zookeeper Martin Franklin said the length of time it took to count the animals varied from department to department.
"I'm lucky in reptiles as we tend to have pretty large animals and it's a walk in the park to count them. We count them every day so we know what we've got but the point is we need to have a snapshot once a year for licensing purposes."
"It's harder for other departments so for example our insects team have a real job on their hands. They might cheat a little bit sometimes and count an entire colony as just one animal but generally speaking, everything is counted.
"Our aquarium guys have a great trick - they take photographs so they can make sure they don't double count anything."
Founded in 1826 by Sir Stamford Raffles, it is the oldest zoological scientific zoo in the world.
Last year saw four Humboldt penguin chicks hatched at Penguin Beach, and the zoo's first-ever aye-aye baby - a type of Lemur - arrived.
The aye-aye, called Malcolm, was born was born on 1 July, but emerged from his secluded nesting box for the first time just before Halloween.