Your love for the ibis may be ironic, but research reveals these notorious native city slickers thrive in urban landscapes by making intelligent decisions based on where you're getting lunch.
BY ANGELA HEATHCOTE
Ibises first started appearing around Sydney back in the 1970s. Before that, they called the Macquarie Marshes in north-west New South Wales home. More than 700 kilometres from the toppling trash of Sydney’s major parks, majestic ibises strode through their lush wetland habitat and soared overhead. But as any resident of Sydney knows, that changed.
“Due to human intervention, the natural functioning of this ecosystem was altered and many waterbirds suffered as a result,” says Australian National University ecologist Matt Chard. “As its available habitats became more and more degraded, the ibis decided to try its chances in the big smoke and has been hugely successful.”
Sydney’s ibises are hardly recognised as the greatly successful urban colonisers they are.
Instead, we know them as ‘bin chickens’ or ‘tip turkeys’, with eyes on the fries and scaly-looking black legs planted firmly on your desired park bench or picnic table. Matt is astonished when people group the ibis with non-native birds such as the common myna or pigeon.
“This is due to either their appearance being similar to that of the sacred ibis from Africa or that they seemed to have appeared in our cities and multiplied exponentially in the last 40 years,” Matt says. “Nevertheless, the Australian white ibis is as Aussie as our kangaroos and koalas.”
They’re also a lot smarter than you think.
Matt has spent more time than most sitting out in the rain observing ibises in Sydney’s central parks. “All up I’ve spent more than 40 hours watching the ibis. I would note what they were doing: resting, grooming, fighting, foraging and, most importantly, whether any food they consumed was natural or from a human source.”
His observations were published in the online journal Urban Ecosystems. The findings revealed individual ibises make calculated daily decisions about where and what they’ll eat, and they read the weather to help them choose.
"The Australian white ibis is as Aussie as our kangaroos and koalas.”
On sunny days, an ibis will position itself in parks with high human visitation, like Belmore or Hyde park, where they know humans will drop food, leave scraps behind or voluntarily feed them. However, if it’s a cloudy or rainy day, they know less humans will be around, so the ibis will travel down to the Domain where they can forage for natural foods like earthworms. Matt says worms are more abundant and easier to catch in rainy weather because flooding pushes them closer to the surface.
“An individual is making an informed decision and weighing up time and energy expenditure with the food reward,” says Matt. “So whether it’s sunshine or rain, the ibises are going home with a full stomach.”
Matt is hoping his new study will show people that the ibis is highly intelligent and here to stay. “Unless we start making significant improvements to their natural habitats, there is no reason for the ibis to move out of our cities. We may not like it, but they are simply trying to survive in the world we have created.”
While Matt doesn’t encourage Sydneysiders to accommodate the bird too much – he envisions it will one day be able to return to the Macquarie Marshes – he wants people to, at the very least, show ibises more respect.
“I have been witness to a few people who go out of their way to cause distress to these birds, which is unacceptable. They may not be the prettiest, but they have grown on me during our time in the parks together and they have quite a bit of personality. I like the ibis and, whether ironically or not, a lot of people are getting behind these birds.”
In 2017, The Guardian ran an online poll to determine, once and for all, which bird was Australia’s favourite. The ibis lobby was so successful it claimed second place, only just losing out to the magpie. And while many of the votes would have been tongue-in-cheek, John Martin, an ecologist from the Royal Botanic Garden Sydney and a key component of the ibis campaign, was on their side the whole time. “Their colonisation of urban areas, and associated shift to a fast-food diet, is a remarkable example of their adaptability,” he told The Guardian following the final announcement.
With increasing urbanisation, Matt predicts the ibis will simply move with us. But he also says other bird species may start calling Sydney home as we continue to degrade natural habitats.
“The unfortunate thing about this is that as species become more urban they will be the ones we humans will take notice of. But these species are the ‘winners’ as there are more species that can’t persist within urban areas than those that can.”
This story was published in Volume 1 of Sweaty City - buy the magazine now for more great environment writing and design!