SYDNEY, AUSTRALIA - APRIL 20:  (NO UK SALES FOR 28 DAYS)  Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge and Prince George of Cambridge meet a Bilby called George as they visit the Bilby Enclosure at Taronga Zoo on April 20, 2014 in Sydney, Australia. The Duke and Duchess of Cambridge are on a three-week tour of Australia and New Zealand, the first official trip overseas with their son, Prince George of Cambridge.  (Photo by Pool/Samir Hussein/WireImage)