38 Australian Geographic
B
ECAUSE CASSOWARIES SPEND most of their time in dense
forest away from the prying eyes of researchers, it is
not surprising that we still know so little about them.
“For a huge bird with bright colours, they only need to take
a few steps off the road into shady rainforest and you can’t see
them,” Wren says. “They are difficult to spend time observ-
ing and studying.”
The bird’s elusive nature has also made it difficult to
accurately assess the species’ population size. The first compre-
hensive survey in the Wet Tropics of Queensland – a World
Heritage area that stretches from just south of Cooktown to
almost Townsville and represents the core of the cassowary’s
range in Australia – was carried out by a team of CSIRO
scientists led by David and published in 2014. The researchers
collected DNA from scats to extrapolate the number of indi-
vidual birds in the region and the results surprised everyone by
revealing a population of up to 4500 cassowaries.
This was great news, because some earlier estimates suggested
as few as 1500 were left. “We had the numbers really wrong,”
Wren says. “We were actually very pleased.” In 2017 the revised
estimate led to the species conservation status being downgraded
from Vulnerable to Least Concern on the IUCN Red List.
Both Wren and David have been involved in recent surveys
on Cape York Peninsula, working alongside traditional-owner
groups. While most of Australia’s cassowaries live in the Wet
Tropics, there are several smaller, little-studied populations in
isolated rainforest pockets further north. The southern cassowary
is also found in New Guinea (alongside the northern and dwarf
cassowary species), where the population numbers 15–45,000
and suitable habitat covers an area about 15 times that in Australia.
To learn more about cassowaries in Cape York’s McIlwraith
Range, 450km north of Cairns, Wren created visual lures – fake
ra in forest f r u it s – to at t ract ca ssowa r ies to ca mera t raps (see Your
Society, AG 149). The images helped her identify individuals
and also captured previously unseen behaviours in both chicks
and male–female pairs.
Cassowaries are culturally important for many far north
Queensland Aboriginal groups, including the Ayapathu, Kaanju,The bird’s elusive nature has also
made it difficult to accurately assess
the species’ population size.
Fragmentation of rainforest habitat is leading to a declining
southern cassowary population. It’s also resulting in more interactions
with people: this hungry uninvited guest turned up for dinner near
Mission Beach in the heart of QLD’s Cassowary Coast.