Wetland wonderland breeds birds' paradise

A once-parched flood plain has become a bustling ''mini Kakadu'' after farmers used irrigation infrastructure to mimic Murrumbidgee flows, writes Debra Jopson.


In a remote reach of NSW, a city of birds has suddenly appeared, building prime waterfront residences in which to pamper their young and feasting on a smorgasbord that floods and rain have brought to the Murrumbidgee.

A wildlife boom inspired by an abundance of water has turned the Lowbidgee flood plain into a noisy, bustling ''mini Kakadu'' as about 20,000 ibises and thousands of other waterbirds including spoonbills and musk ducks make their nests on wetlands which until recently were parched by drought and dams.

''If you had been here 12 months ago you would have seen it at its absolute worst. It was a moonscape,'' said Michael Spinks, a member of a group of landholders on this flood plain between Hay and Balranald.

They use irrigation infrastructure to channel environmental flows to keep the birds happy, mimicking the flows of the mighty Murrumbidgee before it was dammed.


At the Telephone Bank rookery on Torry Plains Station, not far from the grain farm of Steve Blore, the air is rich with the honking and gamey smell of about 5000 straw-necked ibis that have built nests with glossy and white ibises.

Scientists call it a ''major breeding event'' but up close it is a dazzling assembly of lignum-twig nests like woven baskets holding blue or white eggs or wide-mouthed chicks, above which adults perch in trees carrying branches in their beaks for home improvements.

''The Lowbidgee is the most important wetland by far on the Murrumbidgee. There are very few places where you get these mega breeding events occurring,'' says Richard Kingsford, known as ''Professor Duck'', who heads the Australian wetlands and river centre at the University of NSW.


The centre manager, Sharon Ryall, who spent last week wading around the nests checking how many eggs had hatched successfully, says: ''This is a very rare thing. You don't get it very often because of the boom and bust nature of Australia.''

Ryall and research fellow Kate Brandis use a small motorboat to navigate watery roads in the bird city, with tags and waterproof notebooks to document how many young survive.

It is easy to peer right into a nest and to catch a black glossy ibis chick pecking its way out of a bright blue egg, or to see a cluster of week-old crying spoonbill chicks dusted in what looks like white snow - their parents' excrement.

Ryall can answer the question: what's to love about the white ibis?

''The white ibis you see in the parks in Sydney are a beautiful bird in their native habitat. They are not the trash birds you see in Hyde Park,'' she says.

Spinks is hoping that all three ibis species will help defend them from locust attack as authorities warn of the possibility of the worst plague in 30 years.

''We have [1620 hectares] of wheat crop and Steve and I have a rookery at each end. Ibis are known throughout the world as the farmers' friend. They will eat half a kilo in one day - and more when they have fledglings. That's a lot of grasshoppers,'' he says.

It is a mystery where the birds come from, how they know water will be there and where they go afterward.

Blore says: ''How they know has got me beat. I have been out in the swamp when it is dead dry and a duck comes out of a hollow. By the time the chicks are born, the water is there. How do they know that? You see them in the thermals. We say they are sending text messages to their mates - they've got to get up there to get coverage.''

Kingsford says research indicates they make incredible reconnaissance journeys in which they detect the approach of low-pressure weather systems signalling water in their breeding grounds.

''They just belt up and go on a sort of round trip,'' he says.

When a Deakin University scientist, David Roshier, put transmitter devices on grey teal, one from northern NSW flew 1268 kilometres over 10 days, heading west and returning via southern Queensland.

The birds are at the top of the food chain, which begins with vital eggs and seeds set down in soils during one boom event, only to flourish in the next, says Kingsford.

''As soon as that water arrives, the seeds will germinate and the invertebrates will hatch out. There are thousands of species. A sort of invertebrate soup is created,'' he says.

''Waterbirds are generally the first to breed. They arrive, there is a smorgasbord, they build up fat very quickly and as soon as they build up fat, they have the urge to breed.

''That smorgasbord also brings in fish and reptiles.

''You've got this incredibly vibrant community and everything's eating everything else.''

http://www.theage.com.au/environment/conservation/wetland-wonderland-breeds-birds-paradise-20101105-17hl6.html