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 who embarked Thursday 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.

The same scene was being repeated at zoos throughout Britain Thursday - the census is nationwide. No stone is left unturned, lest there be a beetle below.

At the London Zoo, keepers hope the new year will bring some company to Ricky, who has been the zoo's lone rockhopper since 2011.

"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."

In the meerkat enclosure, 11 of the small mammals were only too happy to be counted, climbing onto a keeper's clipboard seeking attention and food.

An all-female family of nine otters likewise rushed forward at the sight of their favored delicacies: Mice and crayfish. In the invertebrates section, a palm-sized red-kneed tarantula called Jill caused a stir among visitors when she was lifted out of her box for inspection.

"This is quite a docile one," said keeper Amy Callaghan, who held the spider out in her hand for photographers. "I was a little bit wary of them at first, but now I think they're brilliant."

The census is required as part of the license terms of British zoos, and the data is used for zoo management and international breeding programs for endangered animals. The final tally could take weeks.

Most animals in the zoo have microchips in their bodies, making counting a little less daunting. Fish and animals with camouflage properties - such as 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 and female Melati, from Perth, Australia. The endangered tigers were matched by an international breeding program to ensure a genetically diverse population of animals.

"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.