Lake Ballard and the Banded Stilts

On a continent where usually waterless salt lakes abound, Lake Ballard is special - very special indeed.

In today’s world, Lake Ballard first came to international prominence in 1995 in the wake of Severe Tropical Cyclone Bobby. Bobby had crossed Western Australia’s Pilbara coast on the 25^th February and, moving inland in a south-easterly direction, this Category 4 storm was to ultimately dump over 400 millimetres of rain across the Goldfields, filling the interconnected salt-lake system comprising lakes Barlee, Marmion and Ballard.  Within days of the lakes filling, Lake Ballard was becoming the destination of tens of thousands of coastal wading birds known as Banded Stilts*.

What happened next had never before been recorded: a Banded Stilt breeding event, captured on film by ABC Television’s Natural History Unit. Eyewitnesses included Clive Minton, Grant Pearson and Jim Lane.  For Wingspan magazine (June, 1995), they wrote:

There was an unbelievable frenzy of activity. The colony had doubled to an estimated 4500 nests within three days, and more birds were settling in every minute. Birds seemed to be bustling in every direction. Aggression associated with mates and nesting selection was widespread. Up to 20 copulations were visible at any time – on the water, on land, in the colony, standing, sitting, walking, swimming (and each lasting an average of 45 seconds!). Incubating birds were leaving the nest and running down to the water to dunk their breast-feathers in the water and have a quick drink before returning to the nest (it was a hot day). It was like a cross between the main street of Tokyo and the ‘red light’ district of Kalgoorlie.

Clearly, our Banded Stilts are not your usual wading bird! They will only nest in colonies and always put their young into creches. What makes them more unusual amongst the world’s many species of coastal waders is that they are rather particular about where they breed. In fact, they won’t consider anything other than a recently-flooded salt lake. This is because their chicks are partial to a special type of brine shrimp, trillions of eggs of which lie dormant under the salty crust of the dry lakes, waiting for a really big rain in order to hatch. These are the Parartemia shrimp and they multiply rapidly because, like the Banded Stilt, this could be their only chance of breeding for many years to come.

The Banded Stilt (Cladorhynchus leucocephalus) is a nomadic stilt from Australia. It belongs to the monotypical genus Cladorhynchus. It gets its name from the red-brown breast band found on breeding adults, but this is mottled or entirely absent in non-breeding adults and juveniles.

So, in February–March 1995, the Banded Stilt’s unique breeding requirements had miraculously been met at Lake Ballard thanks to Cyclone Bobby. Its vast salt crust had been covered in warm shallow water, the long-dormant brine shrimp were once again hatching, and several of the low islands in the middle of the lake were being colonised.

Within days, the first of tens of thousands of Banded Stilts to arrive at Lake Ballard had created innumerable nests out of the ‘island’ sands. The first eggs were laid in early March, less than 12 days after Bobby had swept down from the north. Newly-hatched chicks were taken to the water by one of their parents, receiving a hostile reception from other adults. They pecked at the chicks and even jumped on them while their desperate parents did their best to shield them from this uncharitable behaviour. Once at the water, the chicks formed crèches overseen by one or two adults. Here they  indulged in a feeding frenzy on the swarming schools of brine shrimp.

In the previous 207 years of European settlement, the Banded Stilts were known to have nested just twenty times, with six of these occasions being at Lake Ballard. The seventh occasion would become a landmark event in Australia’s natural history, with the ground-breaking ABC documentary Bobby and the Banded Stilts screening throughout Australia and overseas.