Date: Wednesday, October 12, 2016

Project: Eastern Australian Waterbird Survey

Observer: Richard Kingsford

It was cold in Cunnamulla early this morning when we left – jumper weather. We even had to put the heater on in the plane, unheard of during this part of the aerial survey. First job - the patchwork of small canegrass swamps and claypans that had filled from local rainfall. About 20% of them had water but we still had to fly zig zagging between them. It is a mystery but these canegrass swamps don’t seem to ever support many waterbirds. Perhaps because they fill when there is lots of other water around or they don’t have as much food for waterbirds. 

Surveying a canegrass swamp southwest of Cunnamulla

Then across the upper catchment of the Paroo River, the most westerly river in the Murray-Darling Basin, and the only truly free flowing river, protected by an agreement between the New South Wales and Queensland Governments. In the distance, we could see the two magnificent Currawinya Lakes to the south, Lake Numalla and Lake Wyara - both full. They don’t fall on our survey bands but we survey these as part of our surveys of all the major wetlands in the Murray-Darling Basin, starting in early November. Always a treat, given how productive those systems are. There are then more canegrass swamps and claypans to survey. 

Small creeks fill these canegrass swamps with local rainfall

Our next river to the west was the Bulloo River – now considered part of the Lake Eyre Basin even though it doesn’t connect to those rivers. It stretches a long way east to west, across our survey band. So we flew it for about 20 minutes. The water was coursing down so we couldn’t see the beautiful red rocks in the bed of this river, exposed when the river is low. It was running a ‘banker’, nearly up to the top of its banks before it began to spread out across its distributary system. There was water everywhere. 

Bulloo River in flood, spreading out across its floodplain 

Bulloo River fans out so that you can’t see a main channel, as it fans out across the floodplain through a myriad of channels to fill Bulloo Lake. 

Bulloo Lake with its different patches of lignum and other vegetation, interspersed with islands

The lake often separates into two parts, but not today – it was full and even overflowing to the south where it spills eventually into the vast Caryapundy Swamp, also known as the Bulloo Overflow. As with everywhere we have been, waterbirds are few and far between. Often the lake will have tens of thousands of waterbirds when the more ephemeral rivers and floodplains dry. Today’s tally was less than a thousand but as with everywhere there was breeding action. I saw two coot with broods and a pink-eared duck family. Then we came across one of the great sights on these large floodplain systems – colonies of breeding waterbirds. There were straw-necked ibis, night herons, egrets and white ibis breeding. You can see them flash past on the right hand edge of the video below.  

Colonial waterbirds breeding Bulloo Lake

Breeding colony of straw-necked ibis, egrets, night herons and white ibis on Bulloo Lake

After this, we only found a few ephemeral lakes with patches of water and one or two waterbirds on our way to a crew and plane pits stop at Innamincka.

We knew the Cooper hadn’t got down this far. As we had seen when we were on the band to the north, this year’s flood on the Cooper was nothing like the size of the Diamantina flood. When there is a flood, Lake Hope is one of the key large lakes here for waterbirds but it has been dry for some time. 

Lake Hope is a spectacular lake for waterbirds when it has water 

It was no surprise to see a predominantly dry river bed, along this part of Cooper Creek. There were still some clearly hyper saline patches of water which had the odd red-necked avocet. They are still obviously able to find prey in these inhospitable pools. 

Surveying the few patches of highly saline water along Cooper Creek 

Ferry on the Birdsville Track is high and dry with no water in the river

Surprisingly, way down along the Cooper, Lake Kilalpannina stands out like a jewel in this grey landscape. It has brilliant blue colour caused by its salty water. It was the site for a Lutheran Mission during the late 1800s and early 1900s, before the harshness and droughts forced it to be abandoned. The lake fills normally when Cooper Creek comes down but this hasn’t happened for about four or five years but local rainfall last year filled it and it had obviously been topped up since. Despite the large expanse of water, it only had a few shelduck (mountain duck). It had probably started to become too salty. There seems to be a ‘goldilocks’ stage in these salt lakes when they are really productive when slightly salty but then turn when only the most tolerant invertebrates can survive.  

Lake Kilalpannina, a salt lake on Cooper Creek, still held water from local rainfall

Our planning always starts by scrutinising satellite imagery to try and work out where the water is and how far west we need to go. It is pointless flying into the outback deserts if there is no water. The satellite imagery was a bit ambiguous about water in Lake Eyre. Our survey band cuts through the top of the lake and it looked like the water that comes in from the north, from the Diamantina River was sitting in what is called the Warburton Groove. This is a massive channel which you can see from space, which runs down the middle of the lake. So we needed to check it out. You could see where the water had been but it was just north of our survey band. Even though very shallow, there were silver gulls (seagulls) and even pelicans. We have no idea what the pelicans could be doing there because it is highly unlikely there are any fish. 

The fresh water coming in from the floods to the north in the Georgina-Diamantina Rivers flow into the Warburton River which then carves a the Warburton Groove down the middle of Lake Eyre

Right at the end of the survey band, there was a ‘surprise’ patch of water where Umbum Creek flows into Lake Eyre. It had about 100 swans and a few other waterbirds. These creeks make an important contribution of water to the lake at times. 

Flooded areas with black swans on Umbum Creek, which flows in from the west to Lake Eyre

Stopover was William Creek, the small town west of Lake Eyre. It has more planes than most large country towns, given the growing interest in seeing Lake Eyre from the air. 

William Creek Hotel