With the decline in quality of their wetland habitat west of the Great Dividing Range, Australian White Ibis have taken up residence in many urban centres along Australia’s eastern coastline. They are not always welcomed by the human inhabitants of cities, and in order to manage the conflict that sometimes occurs it is important develop an understanding of bird numbers, movements and site fidelity.
To collect the necessary information, we (myself and John Martin from the Royal Botanic Garden) have been conducting monthly surveys of the ibis population of central Sydney for the last 7 years, with some interesting results. For example, monthly counts of the number of ibis in city parks indicate that there is a consistent influx of ibis into the city each year during the breeding season.
We have also been marking ibis with numbered wing tags and unique combinations of coloured bands, which have demonstrated that some birds are remarkably faithful to particular foraging locations. From more than 5000 records of colour-banded birds, it is apparent that 80% of them spend more than half their time in a particular park.
For example, BlueRedGreenMetal has been recorded 40 times in North Hyde Park, but has never ventured across William Street to South Hyde Park, let alone Belmore Park, Darling Harbour, the Domain or Royal Botanic Garden! Similarly, BlackPinkMetalYellow has been recorded 45 times in South Hyde Park without entering North Hyde Park (and yes, they can still fly with their bands on!).
In contrast, other birds, like RedWhiteYellowMetal are only seen occasionally, going AWOL for a couple of years before returning. Or so we think! We’re not sure what they do between our monthly surveys...
To find out a bit more about their movements, we have just equipped three of our favourite birds with solar-powered satellite transmitters to record their positions at hourly intervals. We will collect data for two months, before re-catching the birds and removing their transmitters.
At the end of this time we will know for sure whether the Hyde Park Sandwich Stealers are totally at home in an artificial environment or whether they periodically join up with the Wetland Wanderers. So if you see an ibis with a solar panel on its back, don’t panic, it is not part of a direct action carbon pollution reduction strategy!
And if you see any ibis (or cockatoos) with coloured wing tags, please assist us in our research by reporting the colour and number to firstname.lastname@example.org.