More than 30,000 pelicans have descended on a river system in New South Wales, in one of the largest breeding events recorded in Australia.
A wet and wild summer across the state created the ideal conditions for the native species to breed at Lake Brewster, in the state's Central West.
"The health of not only Lake Brewster but the whole of the river system — the wetlands that are all part of the habitat — are all in very good condition," Mal Carnegie, from the Lake Cowal Foundation, said.
"Each day those chicks are requiring between half a kilogram and a kilogram of food, so you are looking at between 15 and 30 tonnes of biomass per day to feed the chicks and adults. It's an incredible amount of fish."
Mr Carnegie said it had been "extraordinary" to see the pelican colony develop over the past six months.
The Department of Planning and Environment's senior environmental water manager, Joanne Lenehan, said the scale of the breeding event was very rare.
"Most nesting events are between a few hundred to 6,000 to 8,000, particularly along the coast, so this event is at least twice what we consider a large or average event," she said.
Over the past six months, more than 15,000 nests have been recorded at the lake, surpassing the previous record of 8,000 in 2010-11.
Critical to pelicans' future
The pelican is not regarded as vulnerable or under threat, but population numbers have steadily declined since the 1970s.
"We have seen a loss of nesting sites including Lake Cowal here in the Central West, so these events are important to keep the population healthy.
"Like most water birds, they face challenges from a reduction and change in water flow regimes and loss of habitat due to competition with development of urban environments."
Mr Carnegie said breeding seasons like the one seen at Lake Brewster are vital to preserving the pelican.
"If you think about the life span of a pelican, realistically they only have three, maybe four ,opportunities to contribute in terms of reproduction.
Artificial intelligence, drones and banding
A collaboration between university researchers, conservationists and state officials has led to the use of drones and artificial intelligence to more effectively count the population of the colony.
Mr Carnegie regularly flies a drone over the colony, taking a series of images and videos that are sent to the University of New South Wales where they are analysed by an AI program.
"The information gathered from the drone then helps Water NSW and Environment NSW in terms of supporting the colony with its development."
To further understand the movements of pelicans, over 400 juvenile birds have had bands attached to their legs over the past six months to allow for easy identification.
Ms Lenehan said they hope the tracking of the banded pelicans will uncover vital information about the species.
"Despite this we know very, very little about them, so we hope to answer those age-old questions of how do they know to come inland to breed on these flood events, how far do they move, how far do they forage?"
