Thousands of banded stilts (a small nomadic wading bird) have abandoned wetlands around the Western Australian coast and flocked to Lake Ballard in the Goldfields, about 150km north of Kalgoorlie, after heavy downpours in the region resulted in some areas receiving their entire annual rainfall in just a few days.
Department of Parks and Wildlife Goldfields regional manager Ian Kealley said the recent rains had created a rare opportunity for researchers to tag the stilts with satellite trackers to monitor their breeding patterns.
“We recently assisted researchers from Deakin University on a flyover of Lake Ballard and this revealed thousands of stilts, many of which are nesting,” he said.
“In the past few weeks 12 adult stilts have been fitted with trackers as part of ongoing research by the university.”
Reece Pedler from the Centre for Integrative Ecology at Deakin University said they were keen to learn more about the stilts’ breeding patterns and movement in WA after completing similar studies on Lake Eyre in South Australia.
“In early January, we visited a number of wetlands across the Southwest and selected some sites near Esperance, Katanning, Bunbury and Mandurah that were suitable for tagging stilts, however before we could return, this massive rainfall event intervened and the stilts suddenly departed to lakes in the Goldfields,” he said.
“At this time the satellite images revealed that many previously recorded banded stilt breeding sites in the Goldfields were inundated and a flight over lakes Ballard, Marmion and Goongarrie showed stilts spread across these large saline lakes and a small breeding colony of about 4000 pairs on Lake Ballard.
“With assistance from the Department of Parks and Wildlife, we were able to get out there quickly and assess the nesting colony and attach trackers. We are also particularly interested to see if the tagged stilts move between western and eastern Australia.”
Banded stilts are found throughout south-eastern and south-western Australia and are renowned for their unusual breeding strategy in which they await infrequent large rainfall events in the inland that inundate vast and normally dry salt lakes.
“Banded stilts somehow know it has rained and arrive within days. Here they feast on abundant brine shrimp and build thousands of nests on tiny islands,” Mr Pedler said.
“The last major banded stilt breeding event was recorded in the Goldfields in 1995, after Cyclone Bobby dumped hundreds of millimetres of rain.”