Collaborative efforts to uncover the southern cassowary’s presence in Apudthama National Park
On Gudang Yadhaykenu Country, on the tip of the Cape York Peninsula, a collaborative research team including Traditional Owners, Cape York NRM staff and cassowary biologist Wren McLean, set out to determine if the vulnerable southern cassowary—known locally as ‘wadthuuny’—still roamed the northern, Ussher Point section of Apudthama National Park.
The southern cassowary lives in rainforests and associated habitats of north-east Queensland, from north of Townsville to the tip of Cape York. There are currently 3 sub-populations, 1 in the Wet Tropics and 2 in Cape York. The high seasonal variability of fruit production in Cape York may require migration through dry country between suitable habitats, resulting in larger home ranges for the cassowaries compared to in the richer Wet Tropics.
In the remote wilderness of the Apudthama National Park, surveying for these flightless birds across their potential habitat is challenging. The park’s northern section is not included in many formal cassowary distribution maps, likely due to the lack of records and uncertainty about whether the bird was locally extinct.
Their solitary nature makes them difficult to spot and none of the Traditional Owners consulted by the research team had seen wadthuuny at Ussher Point. The last memory of a sighting at this location was shared by a team member whose grandfather encountered one about 40 years ago.
Over 5 days in June 2022, the research team traversed 28.4km of Gudang Yadhaykenu Country, searching for signs and gathering data to estimate the population’s size, distribution and potential threats. In an exciting start, a southern cassowary walked right into base camp on the first morning before starting the survey! While in the field, the team recorded 14 cassowary signs, equating to a sign every 2.02km.
Cassowaries eat 99% native fleshy fruits and are highly mobile, moving between fruiting trees and spreading seeds in their dung. The research team recorded the available fleshy fruits to inform potential seasonal habitat use and observed any threats to cassowary habitat. They found the area had low rates of feral pig disturbance and no weeds or other feral herbivores.
The team also set camera traps with coloured lures resembling rainforest fruits to attract passing cassowaries. Over 78 days these cameras captured 30 events of at least 10 individual cassowaries, including adults, juveniles and stripey chicks. On average it took 14.8 days for cameras to photograph their first cassowary.
Combining Traditional Owner knowledge and tracking skills with scientific methodology revealed a significant breeding population of cassowaries. With the potential of this population being geographically isolated, inbreeding was identified as a potential threat. Another threat is climate change increasing the frequency and intensity of extreme weather events, such as cyclones and bushfires.
Continued surveys in Cape York are a high priority to address gaps in known cassowary distribution. This work will support future conservation activities, combining First Nations knowledge and modern science to protect the wadthuuny from extinction on Cape York.
This research project was supported by Cape York NRM, through funding from the Australian Government.