Gang-gang Cockatoos are a popular feature of Canberra’s cooler months as they fly down from the surrounding mountains to take refuge from the winter chill in the city’s parks and reserves. Currently, while the rest of us are twiddling our thumbs in lockdown, Canberra’s Gang-gang Cockatoos are busily heeding the arrival of Spring by preparing for their breeding season. Like most young couples looking to start a family, the birds are touring the city’s best locations to find an appropriate nesting site. They are very particular about the form and size of their nesting hollows requiring an average hollow depth of 50.5 cm, an average hollow entrance width of 13.1cm and height of 21.3cm, and the hollow height being approximately 7.5m above the ground. These requirements mean that the Gang-gang Cockatoos are ideally looking for hollows in mature trees.
But as most Canberrans will tell you, finding the perfect home in the current market is extremely difficult and, unfortunately, the bird world is no exception. Competition for nesting hollows is fierce as many species are looking for the same features; including possums, Sulphur Crested Cockatoos, and Galahs. Once the Gang-gangs have secured a hollow they will line it with wood chips and dust before egg-laying. After the egg is laid, both parents will incubate it for 4-6 weeks until the fledgling hatches. Gang-gang Cockatoos being social birds, often form creches where several pairs will nest nearby to one another and share the burdens of parenthood.
Hollow competition isn’t the only threat to Gang-gang Cockatoo populations. The species suffered enormously from the 2019/2020 bushfires in both mortality and habitat loss. It is estimated that the fires impacted the bird’s distribution by 28-36%, reduced the carrying capacity for the species by 40%, and resulted in a 10% reduction of the overall population. This is increasingly concerning when considering that the population has declined by approximately 69% in the previous three generations. It is for these reasons that Canberra’s favourite bird has recently been assessed for national listing in the endangered category. Outcomes from the assessment are not expected until early 2022, but you can see our submission in support of the listing here.
Recent research* conducted during the 2019/2020 summer shed further light on the harsh reality for Gang-gang Cockatoos, a cool temperate species. The study focused on Gang-gang chicks and their wellbeing. Chicks were observed to have died due to heat exhaustion, and on days of extreme heat, other chicks left or attempted to leave their hollows prematurely. In addition to chicks being heat-affected, heavy rains also impacted nesting hollows, with some nesting hollows being flooded out in the next season. This work indicates how particularly vulnerable Gang-gang Cockatoos might be due to the impacts of climate change in the ACT.
As the ACT’s faunal emblem, the Gang-gang, holds a special place in our city’s heart but it also faces a potentially difficult future. Be assured, however, that the Gang-gang Cockatoo’s story is one of hope: loved by many, it has a plethora of allies that will continue to advocate for its protection and conservation. Through their continued hard work it is hopeful that this wonderful animal will remain a feature of our city for many years to come.
If you are interested in being involved in Gang-gang research you can photograph any Gang-gang that you see feeding or entering/ exiting a hollow and post the images on Canberra Nature Map. This data will be used to support an upcoming study.
* Davey, C, and Mulvaney, M. (2020) Report on a survey of breeding activity of the Gang-gang Cockatoo within urban Canberra 2019-2020. Canberra Bird Notes 45: 224-231; See also, Davey, C., Mulvaney M., Tyrrell, T. Rayner, L., (in press) Gang-gang observations during the 2020-21 breeding season, Canberra, ACT. Canberra Bird Notes.