Protecting Our Winter Visitors

By Alexandra De Vylder on July 26, 2019 in News

Dr John Martin with a handsome male Yellow-Tailed Black Cockatoo, by Elie McCarthy.

Imagine: A cry pierces the sky and you look up to see sixty black birds winging toward the coast. There’s another call to your left, and more birds rise from a tree to join the flock of floating jets. Sound familiar? I bet.
Residents of the Eastern Suburbs see this graceful migration every morning and evening in the colder months. But what do we know about Yellow-Tailed Black Cockatoos? Why do so many congregate here? Where do they go in summer? A recent study from UNSW used GPS tracking to answer some of the questions we need to know to support the species.
A love of ‘Yellow-Tails’ prompted Jessica Rooke to design the first comprehensive study of the birds in 2015.
“I began researching them in my own time and found that for such a well-known and iconic Australian bird, we know very little about them,” she said.
Birdlife Australia’s 2015 report described a “declining population trend” for Yellow-Tailed Black Cockatoos across south-eastern Australia, based on observational data. Jessica and her research team wanted detailed information on the Sydney population’s seasonal movements and feeding habits.
So, why are dozens of these cockatoos in Centennial Park and Coogee right now? The study found that the pinecones from non-native trees (such as Maritime Pine, Aleppo Pine and Monterey Pine) attract huge numbers of the birds to these areas in winter. Don’t worry, our icons aren’t putting on airs: they still eat banksia and casuarina seeds elsewhere, and they’ll target any tree with borer insects in the wood.
“And we had no understanding of that at all,” said Jessica’s co-supervisor, Dr John Martin of UNSW. “No one had ever done any research on this species to look at individuals, how they’re moving or what they’re feeding on, so we’re sort of starting with a blank page and trying to fill in the gaps with what this species is doing.”
The researchers fitted twelve Yellow-Tailed Black Cockatoos in Centennial Park with solar GPS transmitters to find out exactly where they travelled over a two-year period. They weren’t sure the tech would work. “Because as you can imagine, these birds have crushing can-opening beaks, and the idea of putting something the size of a matchbox on their backs that has a solar panel and a battery in it – they could destroy that piece of equipment pretty quickly if they wanted to!”
The birds left the trackers intact, and the study found that some of them travel as far as 154km away between September and February, their nesting season. This is when pinecone availability in the Eastern Suburbs is low and the birds will find other food sources in agricultural and natural habitat, as well as “highly modified urban areas”.
Loss of foraging and nesting habitat due to land clearing has seen Australia’s four other black cockatoo species listed as endangered or vulnerable to extinction. While our Yellow-Tailed Black Cockatoos aren’t considered threatened, John and Jessica encourage further research to prevent population decline. This includes co-ordinated citizen science efforts, ideally twice a year or quarterly.
“In part, it’d be great if we could have a larger community involvement in monitoring the Yellow-Tailed Black Cockatoo population nationally,” said John.
You can help by reporting sightings of the birds to the eBird mobile app, or BirdLife Australia’s program, Birdata. This data informs state, national and global collections of biodiversity data.
“The idea, even if you just did it once a year, if everyone went out over one week and tried to count all the Yellow-Tailed Black Cockatoos they saw, that would be fantastic. That would be the best data that we have available.”
In the meantime, enjoy these cheeky winter wonders.