In the 1980s, tropical Queensland was The good life attracted not only the rich and famous, but also a charismatic species of migratory bird. Forty years on, the Capricorn silvereyes on have rapidly changed to the point they’ve become genetically distinct from other populations of the species. And that's because unlike the tourists, this insular group of around 1,000 is refusing to return to the mainland.
“There's a lot of food. Around the resort they've had silvereyes in their kitchen stealing fatty foods. They really love fat.
They like dairy products, like yoghurt and cheese, as it gives them a bit of protein and a bit of fat content,” animal ecologist Dr Dominique Potvin told Yahoo News. While these luxuries keep the Lady Elliot Island silvereyes population close to the resort, it’s not the only reason the birds are refusing to leave. Similar behaviour has been documented at another Great Barrier Reef location, Heron Island — where they’ve become very insular and intolerant of outsiders.
Based at the Potvin has been leading research into physical and behavioural changes on the two islands that have occurred once the birds became isolated. “Mainland silvereyes tend to move around quite a bit, but it appears when they set up populations on islands after a few generations they stop dispersing so much, and stop migrating,” she said. “We don't fully understand why that is.
It could be a combination of the environment — the weather and food availability does.