Australia's inland ecosystems have been thriving after a few very wet years but the boom may be starting to bust, and the first sign is dead pelicans.
WARNING: This story contains graphic content that may disturb some readers.
By the middle of summer this year 30,000 of the waterbirds had flocked to Lake Brewster, near Hillston, in western New South Wales.
It was one of the nation's largest breeding events ever recorded – a sight to behold.
"In most cases everything has gone completely bonkers crazy," local ecologist Adam Kereszy said.
The season has now changed.
Mortality rates have climbed and there are warnings dead pelicans could become a common sight across the Central West.
A 5 per cent death rate was expected but Mr Kereszy said that was nothing out-of-the-ordinary.
Today about 3,000 pelicans are left at Lake Brewster and many of those are not strong enough to fly away to search for more food and would not make it through the winter.
"The fit birds basically fly away and the weak ones stay there," Mr Kereszy said.
They must leave because they have eaten most of the carp in the lake, which are the "biggest enemy" for inland waterways, he said.
"They've more or less eaten themselves out of house and home, which is also normal for inland Australia," he said.
Adult pelicans need up to two kilograms of fish per day to survive.
The young ones consume anywhere from 300 to 800 grams, meaning all up about 30,000 tonnes were being gobbled up daily.
"It's an awful lot of fish," he said.
Searching for food
Dead pelicans have been sighted at nearby Lake Cargelligo, further west at West Wyalong and even as far east as Cowra, which is about 300km as the crow flies.
Recent autopsies have found they were attempting to survive on just algae and sticks.
Meanwhile, the ones who do make the journey are expected to be headed further inland to Lake Eyre in South Australia, or the other way to the coast.
"If you see more dead pelicans than usual that's just [because] of this natural cycle," he said.
If the wet winter outlook comes to fruition Mr Kereszy said fish numbers would build back up and they could return to Lake Brewster come October.
A positive sign for a bird that has had a declining population.
In the meantime, he said, fewer carp and birds meant less competition for the smaller native species.
