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Date: Wednesday October 30th 2024

Project:ÌýEastern Australian Waterbird Survey

°¿²ú²õ±ð°ù±¹±ð°ù²õ: John Porter (NSW DPE), Jody O'Connor (MDBA)

±Ê¾±±ô´Ç³Ù: Thomas Clark

Another clear morning for us as we prepared the aircraft to depart Bourke knowing the increasing temperatures during the day would mean increasingly bumpy conditions.

Our first task for the day was Lake Cowal. It is a shallow temporary wetland that can expand to over 13,000 ha when full making it one of the largest in the region. Lake Cowal holds deep cultural and spiritual significance for the Wiradjuri people, the traditional custodians of the land. The area around the lake has many Indigenous heritage sites, including middens, scarred trees, and rock formations.

Lake Cowal

Lake Cowal is the focus of several innovative conservation and management programs run by the Lake Cowal Conservation Foundation () - a non-profit organisation dedicated to the conservation and sustainable management of Lake Cowal and its surrounding areas.

Our counting over the Lake was fast and furious – thousands of Grey Teal, and large numbers of Pacific Black Duck, Wood Duck, Pink-eared Duck, Pelicans, spoonbills, cormorants, ibis, egrets, herons, terns and grebes. There was a sizeable colony of several thousand Straw Necked-Ibis beginning to lay eggs and they were a spectacular sight as we swooped past.

Lake Cowal Straw-necked Ibis colony

Flying west we headed on to count Lake Brewster – a large regulated wetland that is used to store irrigation water, distribute environmental allocations and sometimes supports one of the largest pelican rookeries in the state. However, today we found only low numbers of waterbirds mainly Grey Teal, Pacific Black Duck, cormorant and Pelicans – but no breeding.

Lake Brewster

Continuing west we set our sights on the Booligal wetlands – a complex system of braided waterways and huge floodplains with lignum swamps, marshes, chenopod shrubs and sedgeland that are hydrologically connected to and fed by water from the Lachlan River. When flooded these wetlands cover massive areas and can support huge breeding colonies of waterbirds – in 2012 there was a colony of over 200,000 Straw-necked Ibis, one of the largest ever recorded in the state. Today however we found relatively dry conditions with only moderate numbers of waterbirds – mainly Grey Teal, Pacific Black Duck, coot Pink-eared Duck, Hardhead Duck, Black Swans, spoonbills, ibis, egrets, herons and terns.

Merrowie Creek

Merrowie Creek

Merrowie Creek

Lake Tarwong

Counting on Lake Waljeers south of Merrowie Creek

Our last objective for the day was the Great Cumbung Swamp – a huge expanse of reed beds, grasses and sedgeland fringed by red gum woodland. This wetland can support significant numbers of waterbirds including threatened species such as Australian Bittern. As we criss-crossed the reed beds with systematic survey transects we found drier conditions than the previous two years and low to moderate numbers of waterbirds mainly Grey Teal, Pacific Black Duck, Black Swans, Pelicans, ibis, spoonbills, egrets and herons.

Great Cumbung swamp reedbeds

Great Cumbung swamp reedbeds

Great Cumbung swamp reedbeds

ÌýOur final stop for the day was Griffith.