Sydney cockatoos take over Royal Botanic Gardens 9-year-old Isabella with cockatoos in the Botanic Gardens. WHAT do Heineken and Sydney cockatoos have in common? Both have a habit of sneaking up on you. The bats are gone - now it's time for the Royal Botanic Garden's show-off sulphur-crested cockatoos to enjoy the stardom they deserve. Sydneysiders are asked to help trace and befriend the cheeky birds, whom experts have fitted with wing-tags. 9-year-old Isabella in Sydney's Royal Botanic Gardens. The have also named all the birds. Heineken, bird 012, is one of the Garden's more inquisitive cockies, flying down to land on visitors' shoulders. Every day up to 80 cockatoos visit the harbourside precinct, but a joint study between the Garden and the University of Sydney seeks to establish the size of the flock - suspected to be in the hundreds - as well as where they go to eat, breed and sleep, and what prompts them to fly down to perch on the shoulders of random humans. "We are trying to get a good understanding of what the birds are doing, how they behave, where it is occurring and how many are there," John Martin, Garden officer of the Royal Botanic Garden, said. "The study relies on people's curiosity and engagement with the birds," Dr Martin said. Thanks to people's involvement we've discovered the cockatoos have travelled as far south as Loftus and even to Dee Why in the north. The Botanic Gardens recently emerged triumphant from its $2.2 million battle to expel the despised tree-destroying bats by blasting them with heavy-metal music. If you see a tagged cockatoo around Sydney, email cock-atoo.wingtag@gmail.com or visit facebook.com/CockatooWingtags One of Sydney's resident cockatoos in the Royal Botanic Gardens.