From penguins to parrots to primates - zoos across Britain have started the huge task of counting every animal in their collection for a new year census.
Zookeepers faced several tough challenges, such as finding a suitable way of counting thousands of tiny insects to distinguishing one meerkat from another.
The count, which can take up to four weeks to complete, is particularly important for endangered species, where a dramatic change in population could lead to instinction.
ITV News correspondent Rupert Evelyn reports:
There are several new additions at Bristol Zoo Gardens to count, including, a critically endangered golden lion tamarin, a baby ring-tailed lemur, two fruit bats and a Brazilian tapir.
The data collected will be shared worldwide in a bid to help with breeding programmes.
At London Zoo,Ricky the penguin will be the only rockhopper to be counted in this year's stocktake and staff are hoping to find him a mate.
Speaking about Ricky, whose yellow feathers mark him out from all the others, David Field, London Zoo's director, said:
Adrian Walls, team leader of birds, added:
Zookeepers recorded 17,519 animals in last year's count, with 767 species, but new arrivals mean that number could increase for 2013.
The data is submitted to the British and Irish Association of Zoos and Aquariums (Biaza), the national professional body for zoo management and animal welfare.