©London News Picures. A Zoo keeper holds aDumerils boa snake before making a record of their numbers at London Zoo as part of the zoo's annual stocktake on January 4, 2011 in London, England. ZSL London Zoo is home to over 650 different species which all need to be cataloged in their annual stocktake which is a compulsory requirement for their zoo license.Photo credit should read Fuat Akyuz/London News Pictures.