The largest Australian pelican (Pelecanus conspicillatus) breeding event in over 30 years at Lake Brewster has been ongoing since October 2021. Over 15,000 nests were estimated from drone monitoring in January 2022, and thousands of large chicks and juveniles were still on the breeding mounds in May 2022. This is the largest known breeding event in the regulated, inland Murray Darling Basin (MDB) in the 2021–22 water year, and was featured on Central West ABC [https://www.abc.net.au/news/2022-05-03/tens-of-thousand-of-pelicans-descend-on-central/13865160].
The largest breeding events in Australia have occurred at such inland lakes, particularly Lake Eyre where in 1990 over 100,000 pelicans nested and 90,000 chicks fledged in the most successful pelican breeding event on record in Australia. A large breeding event is in the order of >5,000 nests. Lake Brewster is an important site for pelicans as it one of the few sites in the Murray Darling Basin where pelicans breed in such large numbers on a semi-regular basis. This includes events in 2010–11, 2016–17 and now 2021–22. It was the only inland regulated MDB site where several hundred juveniles fledged in 2020–21.
The three key ingredients in general for successful breeding are: 1) protection from predators and disturbance, 2) an abundance of food, and 3) water levels remain in a range at the site that nests are not flooded nor rapidly drop and breeding mounds become landlocked. Lake Brewster is the only site in the Lachlan Catchment that now meets those requirements. This is partly due to a highly successful ongoing partnership between environmental water holders and managers (NSW Department of Planning and Environment and Commonwealth Environmental Water Office), and Lake Brewster’s asset managers, WaterNSW. WaterNSW staff assist in monitoring and research, and manage water levels at the storage based on expert advice facilitated by DPE and CEWO, with any foregone storage volumes or volumes delivered debited from environmental water accounts.
For such an iconic well-known Australian waterbird, there remains many mysteries. Some of the more commonly asked questions are around ‘how do so many birds all turn up at the same location when conditions are ideal for breeding?’