Siberian visitors flock to South Australia’s wetlands

Posted 20 October 2020.

As the first warm breath of spring is felt around the shores of Lake Alexandrina a flurry of activity can be seen across and above the muddy flats of its fringing wetlands.

Murraylands and Riverland Landscape Board wetland ecologist Sam Hardy said each year thousands of wading birds migrate to southern Australia, reaching the end of their incredible journey along the East Asia/Australasia flyway.

“They come from places such as eastern Siberia and Alaska in the northern hemisphere making their way to the estuaries, lakes and other wetland environments along our southern shoreline,” he said.

“Some of these birds have made a flight of more than 10,000 kilometres to reach the Lower Lakes in South Australia, which is recognised as the longest continuous journey recorded for any land bird.

“Recently, our keen birdwatching volunteers at Tolderol on the north western shoreline of Lake Alexandrina, have spotted sharp-tailed sandpipers, curlew sandpipers and red-necked stints among the first arrivals.

So far the incoming migratory flocks are made up almost entirely of mature birds, returning to Australia following their breeding season in the northern hemisphere.

“We expect to see younger birds arrive later in the spring, they tend to leave their nest sites a little later than the adults, once they’ve grown a bit and put on some flying condition, they also take a little more time to make the journey,” Mr Hardy said.

These migratory waders are generally omnivorous, eating aquatic insects and their larvae, as well as worms, small shellfish, crustaceans and sometimes seeds. They feed mainly on the exposed mudflats around wetlands, lakes or tidal areas.

The Coorong and Lakes Alexandrina and Albert Ramsar site is more than 140,000 hectares in area and meets eight of the nine criteria necessary to be designated a ‘Wetland of International Importance’.

By comparison the relatively small, Tolderol Wetland is only 106 hectares, but meets roughly half of the nine criteria by itself, making this site a vitally important part of the greater Ramsar Wetland Complex, Mr Hardy said.

Around 85 bird species have been recorded at Tolderol, 25 of which are listed under international migratory bird conservation agreements, to which Australia is a signatory.

Tolderol is one the most productive food resource sites around the Lower Lakes and is critical to enabling these international migratory bird species to make the incredible annual journey between the far-northern and southern hemispheres.

The work is supported by the Commonwealth Environmental Water Holder and the Murraylands and Riverland Landscape Board through funding from the Australian Government's National Landcare Program, and the landscape levies.