Zookeepers across the country are starting to log all of the animals in their care in a huge New Year stock take. Zoos are required by law to keep precise records of every animal birth, death, arrival and departure. Bristol zoo alone has over 450 species and counting them has thrown up some surprising chanllenges. Nigel Simpson, curator of birds, said the hatching of 11 African penguin chicks in 2008 boosted the zoo's colony to 71. He said: "Monitoring a growing penguin colony is important as we need to know who is who and, although the birds do have a unique spot pattern, they are not easily distinguished from one another." He added: "We get round this by fitting silicone bands on the penguins' flippers. Each band has a unique number so that we can easily identify and count our penguins." The headcount takes place every January, with all zoos and aquariums taking part. Local authorities then use the records to decide whether to issue and renew licences. Dr Miranda Stevenson, director of the British and Irish Association of Zoos and Aquariums (Biaza), said: "The annual stock-take is a big job so January is a busy time of year for many zoos across the UK. "Therefore when zoos submit data to these central databases, it means that we can run detailed and scientifically-based breeding programmes to safeguard these valuable and threatened species."