Among the hundreds of hours of data recorded by an Aussie flight crew across one third of the country, many of them had one “distressing” thing in common. The number of waterbirds on lakes and river systems had plummeted.
University of NSW researchers found a 50 per cent drop in numbers when compared to 2023 — from 579,641 down to to 287,231. While this may seem dramatic, over the 42 years the survey has been conducted this year’s result would be in the middle. But that doesn’t mean all is well.
Although populations of the 70 species counted are known to boom with heavy rains and bust during drought, the survey’s leader Professor Richard Kingsford has noted something worrying — the baseline has shifted.
“It’s like a bouncing tennis ball. The bounces are still there in the wet times, but because the baseline is declining they don’t go as high,” he told Yahoo News.
“I’m not yet convinced that we’ve bottomed out yet, I think there are big lag effects. And all the research is telling us South Eastern and South Western Australia are getting drier, which means less runoff and less water in the rivers.”
Want more stories about our weird and wonderful natural world? 😳🪲 Subscribe to our newsletter.
The birds are counted out loud in the same manner someone might call a horse race. Source: Richard Kingsford/UNSW Sydney
The change occurred after wet La Niña years with widespread flooding saw numbers “bounce” higher than average until this year, and they’ve fallen hard as the weather has dried out. Not only were fewer birds counted but the number seen breeding was also low.
Even the Australian white ibis, which appears to be flourishing in Sydney and Brisbane, was nesting in lower numbers across rural and remote areas.
How are the birds counted?
The birds have been counted using the same method for decades. They’ve tried using photographs and video but neither of these works. Instead, the plane flies at 50 metres above the water, and expert surveyors count the birds “like race callers” and record their commentary to tape.
While Kingsford describes flying over NSW, Victoria, South Australia and Queensland every year as a “privilege”, the dark side of his research is returning to once flourishing waterways and finding them abandoned.
“It can be pretty depressing,” he said.
Kingsford welcomes the work led by the federal government to increase environmental water flows around the Murray Darling Basin. He believes communities along other river systems are paying attention to historical mistakes made by regulators that allowed too much water to be removed upstream, robbing communities, forests, fish and wildlife of adequate supply, and driving its rivers and floodplains to the point of ecological collapse.
“Like so much of the world’s biodiversity, it’s really habitat loss and degradation that’s the overwhelming factor. The building of dams and development of rivers, and taking water out of rivers that don’t go into wetlands means there’s just not the areas for these birds to breed that there used to be,” he said.
Duck shooting ‘straw on camel’s back’ as habitat loss reduces numbers
While duck shooting has been banned in NSW and Queensland, further south in South Australia there’s an annual season every year. In Victoria, an inquiry into its duck shooting season initiated by the Andrews government found the activity should be banned, in line with the sentiment of 66 per cent of the public.
Fewer nesting grounds were sighted by the survey crew. Source: Richard Kingsford/UNSW Sydney
While the RSPCA and Wildlife Victoria welcomed the decision, the Victorian branch of the Construction, Forestry and Maritime Employees Union (CFMEU) opposed it. The Electrical Trades Union (ETU) even threatened to walk off major state construction projects if the ban went ahead. After Jacinta Allen took over as premier, she reportedly used her powers to make a “captain’s call” and permit duck shooting to continue.
A 2017 analysis by Kingsford and his team observed some impact on game species by recreational shooters in South Australia and Victoria. But, like climate change he sees the activity as a much smaller pressure on populations than habitat loss.
“Those things are more straws on the back of the camel, rather than the overwhelming burden of building a large dam that takes a lot of the floodwaters out of a river,” Kingsford said.
Love Australia’s weird and wonderful environment? 🐊🦘😳 Get our new newsletter showcasing the week’s best stories.