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SOUTHERN CASSOWARY
Photo: Courtesy of Damon Ramsey
BSc.(Zool) Biologist Guide
Booming in cassowaries:
Is it ultrasonic communication?
SOUTHERN CASSOWARY:
Casuarius
casarius 200 cm
- The Cassowary has Gondwanaland origins (when
much more of Australia was covered by rainforests).
- There are two other cassowary species in New Guinea.
- It lives to about 50 years of age.
- Despite being a bird, the Cassowary is Australia’s largest land animal.
- It normally weighs about 60kg, but the heaviest recorded was 83kg.
- Its eggs are the third largest of all birds at an average 584g (after the
Ostrich eggs at 1100g and Emu eggs at 637g).
- Even though it is large and colourful, it can be hard to see in the rainforest.
At close quarters it may be quite frightening.
- It has powerful legs and if provoked may kick in defence. The sharp nails on
its inner toes can easily rip flesh so the Cassowary is capable of killing
humans.
- Unable to fly, all it has is the vestigial remains of wings. These have 3-5
large wire-like feathers attached that help brush aside any plants in its
travelling path. As it moves it also holds its head down for protection and lifts its toes
right up under its chin.
- Its hard casque or helmet comprises a central cartilage core and an outer tough
horn-like skin covering. Its size is possibly significant in determining social status.
- The Cassowary is an endangered species, with estimates of only 1500
remaining.
- This
means there may be fewer Cassowaries in Australia than Pandas in China.
- It has
relatives such as the Elephant Bird of Madagascar and the moas of New Zealand
that became extinct after contact with humans.
- Its extinction could affect rainforest plant diversity as it helps spread the
seeds of up to 100 tree and shrub species.
- Its short digestive system allows it to eat the fruits of poisonous
plants by eliminating the toxins before absorbing them. This seems to be associated with
a highly active liver and an unusual combination of stomach enzymes.
- Seeds usually remain
intact and can grow after passing through the bird. Accordingly, the
Cassowary is often referred to as a ‘keystone species’ in seed dispersal.
- Other animals such as the Musky Rat Kangaroo often include part-digested fruit
from the Cassowary’s droppings in their diets.
Breeding:
- The only time the Cassowary is not solitary is during the breeding season. At other
times, if there is an accidental meeting, the female is
dominant (it is larger with brighter colours).
- A female often lay eggs in more than one male's nest, but then leaves the family
responsibilities to them! The male incubates the eggs (for
about 50 days) and looks after the young until he becomes intolerant of them and chases
them away at about one year of age.
- 4 or 5 blue-green eggs are laid from May/June to October/November.
- The chicks are striped until they are about 6-9 months old and become a
glossy black colour when they are about 3 years old.
Additional Information
- 'Henry' was a well-known Cassowary living in the Lake Barrine region. He was born
in
November 1989 in the Gadgarra State Forest a short distance to the east. Being
constantly
surrounded by humans since his birth, he was easily approachable (unlike other
cassowaries).
- In his youth he was a regular visitor to the clearing at
Chambers Wildlife
Rainforest Lodge
.
- 'Henry' had the advantage of easily finding food (given to him by his many
visitors) without having to travel throughout the rainforest in search of the freshest
fallen fruits for himself.
- His residence at Lake Barrine was a tourist drawcard but caused several
problems. In particular, he was a hazard to traffic and finally died
after a minor collision with a truck.
Some Ways to Help:
- It’s best not to stop if you see a Cassowary on the road, but to slow down
instead. This is to prevent encouragement of the bird’s interest in cars and to
reduce its risk of being hit or causing an accident.
- Do not feed a Cassowary as this reinforces its interest in people and contributes
to its fearless attitude.
- When driving near a Cassowary, move away quickly so the bird will become
disinterested.
- Keep car doors and windows closed to exclude cassowaries.
- Please inform others of these suggestions.
Additional Information: Courtesy of Damon Ramsey
-
This is a very large, flightless
bird, almost as tall as a person.
-
Adults are covered in black hair like
feathers. The neck is covered in bright red and blue skin and there is a casque
atop the head.
Tracks and scats
-
The scat of this large bird is
equally and appropriately large and is often found in a conspicuous place, (for
example, on a walking track), with lots of undigested seeds and the occasional
sprouting greenery.
-
Tracks are distinctive; large and
three toed, with the middle toe much longer then the outside toes,
distinguishing it from the Emu.
Habitat and distribution
-
The Cassowary usually inhabits
tropical rainforest, but also utilizes associated woodlands, mangroves, beaches
and is known to steal fruit from backyards and farms.
-
It is restricted to the
north east of Australia, and New Guinea. Within it's rainforest habitat it is
the largest native animal.
Ecology
-
It is considered a vital
“keystone” species known to eat, (and therefore distribute) various large
tropical rainforest fruits. In fact, the
cassowary is probably the single most important animal seed disperser of the
local rainforest.
-
Studies have shown that the animal is an obligate frugivore,
with the bird depending on fruits to survive (Stocker and Irvine 1993).
-
So far,
over 200 rainforest plants have been recorded to be eaten by cassowaries (Kroon
and Westcott 2001).
-
The relationship may be equally dependent in the other
direction. One study recorded 78 species found in Cassowary dung, with at least
some of the seeds of 70 of those species remaining viable (Stocker and Irvine
1983).
-
As with many fruit specialists, many of the seeds come out virtually
untouched and many of these are far too large for any other extant animal,
except for the cassowary, to disperse (Stocker and Irvine 1983).
-
And even though
the bird itself is hard to see, their scat can be quite common and conspicuous,
and can contain up to 1 kilogram of seed (Stocker and Irvine 1983).
-
One scat
contained 13 seeds of about of about 6 centimetres in diameter (Stocker and
Irvine 1983).
-
Being large animals, Cassowaries also have the
potential to be effective dispersers over some distance.
-
Radio-telemetry showed
that cassowaries, especially in the uplands, had huge territories, sometimes of
several kilometres, and may cover that distance in a day (Kroon and Westcott
2001).
-
Further, seeds may take over 10 hours to pass through the digestive
system (Stocker and Irvine 1983), thus cassowary dispersed seeds have the
potential to be dispersed quite widely.
Behaviour
Script: Courtesy of Damon Ramsey BSc.(Zool) Biologist Guide
Additional Southern Cassowary Photos
Revegetation
Tips To Ensure the Cassowaries survival
Cassowary Food Plant
List
Cassowary
Workshop
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