LONDON (AP) -- In a sea of flapping black and white flippers, Ricky is hard to miss: He's got spiky yellow feathers, a flamboyant character, and he's the only rockhopper among the dozens of penguins living in the London Zoo.
That's a big help for keepers embarking on their annual stock-taking of all the zoo's residents. It's no easy task, when there are more than 17,500 creatures to count. All animals have to be accounted for, including the tarantulas, locusts and snails.
Zoo managers started the painstaking process on Thursday, and the final tally could take weeks.
Officials hope this year will bring new partners and families to a range of animals. An all-female family of nine otters has been waiting for a new male to arrive, and Ricky, who has been the lone rockhopper in the zoo since 2011, would also appreciate a mate.
"Ricky's quite a unique character — he was rejected by his parents and was hand-reared. He's more interested in zoo keepers than in other penguins," said zoological director David Field. "It's time to get him some rockhopper partners."
The census is required as part of the zoo's license terms, and the data is used for zoo management and international breeding programs for endangered animals.
Most animals in the zoo have microchips in their bodies, making counting a little less daunting. Fish and animals with camouflage properties — like leaf insects — are trickier, and the tiniest ones such as ants are counted in colonies, not as individuals.
New additions to the zoo being counted for the first time included baby Ziggy, an endangered white-naped mangabey monkey, and Maxilla, a black-and-white colobus monkey.
The zoo also welcomed a pair of new Sumatran tigers — male Jae Jae from a zoo in Ohio in the U.S. and female Melati, from Perth, Australia.
The tigers were matched by an international breeding program to ensure a genetically diverse population of animals. They will soon be properly introduced to each other and meet visitors in a newly expanded enclosure in spring.
"We breed them in the zoo because they are running out of time in the wild," said Field, who's hopeful the tigers will soon produce cubs.
The World Wildlife Fund says there are now fewer than 400 of the big cats, which are native to Indonesia.