In pictures: The great London Zoo animal count
Thousands of animals at London Zoo are being counted as zookeepers begin their annual stock-take.
The count is a compulsory requirement for the zoo to keep its licence.
The information collected is shared with zoos around the world via the International Species Information System and is used to manage worldwide breeding programmes for endangered animals.
In 2015, 17,480 animals and 756 species were counted.
'Cause for celebration'
In 2015, the zoo welcomed many new arrivals including the world's first zoo-bred Lake Oku clawed frogs.
A spokesperson for the zoo said: "The 14 tadpoles were a real cause for celebration as these totally aquatic frogs, native only to Lake Oku, in Western Cameroon, Africa, are some of the most genetically unusual creatures in the world, having developed extra chromosomes throughout their evolution."
Edward the two-toed sloth was born in July and Gernot, a male Western-lowland gorilla, was born to 22-year-old mum Effie in November.
Gernot is the second offspring of silverback Kumbuka and increases the size of the troop to six gorillas.
A lively litter of 11 African hunting dog puppies also saw the pack more than treble in size.
But zookeepers had to say goodbye to Partula snails. They were reintroduced to their native Tahiti in 2015 to save the species from extinction.
How are the animals counted?
While for some keepers the task is simple, others use imaginative tactics to account for every creature.
Tiny insects like ants are counted in colonies, but all others are recorded individually.