Date: Thursday, October 25, 2018
Project: Eastern Australian Waterbird Survey
Observer: John Porter
Clear blue skies greet us as we head out of Warrnambool towards the Coorong in South Australia – hoping the improved weather conditions hold ! As an added bonus, we immediately encounter higher numbers of waterbirds than anywhere else we’ve sampled in the last few days. Terns, Grey teal, Mountain duck, Black swans, Avocets and migratory waders are all abundant – but the star of the show is big flocks of Banded stilts – our resident salt lake specialists. This species can somehow detect when remote inland salt lakes fill with water and turn up ready to breed within a matter of days, where they feed on the huge pulse of invertebrates that emerges from newly flooded sediments.
Banded stilts on the southern Coorong in South Australia – how many can you count ?? Try doing it within 5 seconds (Photo: Terry Korn)
We also find water and large numbers of waterbirds in the nearby freshwater wetlands south of Watervale – but we also see the damage caused by large scale drainage works that seem to grown unchecked every year causing these crucially important wetlands to reduce in size and frequency of flooding. Most of these wetlands have clear water and support abundant aquatic plant communities, clearly visible as we fly over and highly attractive to Black swans and Coot, as well as the dabbling ducks such as Grey teal and Black duck.
Recently constructed drains continue to impact important freshwater wetlands near Watervale in South Australia (Photo: John Porter)
A freshwater wetland south of Watervale in South Australia with clear water and abundant aquatic plants (Photo: Terry Korn)
As we push eastward into Victoria conditions become considerably drier and many of the wetlands we survey regularly are dry and dusty. The temperature rises, as does the wind and flying again becomes more turbulent and bumpy. Approaching the town of Dimboola we find the aptly named Pink Lake – with its bloom of red algae producing the amazing colour; unfortunately this salty rose pink lake currently supports few waterbirds. Perhaps if the fossil flamingos that were found throughout central Australia 25 million years ago were still living they would judge this lake to be prime habitat - with little competition from other birds!
Pink Lake near Dimboola in Victoria (Photo: John Porter)
After refuelling at Horsham we continue east, encountering many dry wetlands and far fewer waterbirds than our mornings work delivered. Most of the Cooper Lakes (Wallenjoe wetlands) system are dry – but a few of the Lakes hold water and moderate numbers of waterbirds including Mountain duck, Pelicans, Coot and some Purple swamphens nesting in the reed beds.
Our next stop is Waranga Basin - a large deep water reservoir that has low numbers of waterbirds, mainly Cormorants, Terns, Pelicans and small numbers of Grey teal and Mountain duck. Further east near the town of Benalla we arrive at Lake Mokoan to find it dry except for some tiny puddles of water with few waterbirds; another sign of the persistent and widespread dry conditions throughout much of eastern Australia.