LONDON, ENGLAND - AUGUST 21: Alberta the 444g Tawny Owl on the scales at London Zoo on August 21, 2013 in London, England. The height and mass of every animal in the zoo, of which there are over 16,000, needs to be recorded. The measurements are collated in the Zoological Information Management System, from which zoologists can use the data to compare information on thousands of endangered species. (Photo by Bethany Clarke/Getty Images)
