© Licensed to London News Pictures. 22/08/2012.  London, UK. Elton the Spectacled Owl, who is 9 weeks old, sits on specially prepared scales. He weighed 634 grammes. ZSL London Zoo conducts its annual weigh-in. Each of the 16,000 animals are measured and weighed. The information recorded is sent to zoos around the world. Photo credit : Stephen Simpson/LNP