Australia has a number of unique flora and fauna. Included among these is the mallee fowl which was once found over large areas of the continent. It is now facing extinction. It belongs to the megapod family (big feet), most of whom frequent tropical or subtropical areas of high rainfall. However the malleefowl is a species of the lower rainfall, southern Australian regions. Scrub fowls and brush-turkeys are other examples of megapodes.
'Mallee' is the name given both to the main district where they are found ie north east Victoria, and the semi-arid eucalypt woodland that is found there.
Megapodes are also known as incubator birds or mound-builders. They are stocky, quite large birds with small heads and large feet. Megapodes are mainly terrestrial and are browsers. Most are brown or black. They also hatch in the most mature condition of any birds, a state known as superprecocial. In the case of the malleefowl, they hatch with open eyes and full feathering. Within an hour they can run at speed and at a day old they are able to fly.
The mallee fowl is now reduced to three isolated populations – the Murray-Murrumbidgee basin, the fringes of the Simpson Desert west of Spencer Gulf and the semi-arid fringe of Western Australia's south-west corner. Its natural habitat is woodlands of dry, low eucalypts and/or semi-arid mallee scrub.
Its scientific name is Leipoa ocellata (ocellata meaning 'eye-marked egg-leaver) and it is one of the twenty-two bird species that make up the Megapodiidae family. It is also known as 'gnow' and 'lowan', both aboriginal words. The town of Gnowangerup in Western Australia is derived from the aboriginal 'gnow' meaning mallee fowl.
An abandoned mallee fowl nest has been fenced and signposted on the Holland Track. For a 4WD adventure tour, driving the 700-odd kilometres of Holland Track gives a fascinating glimpse of one of Western Australia's more isolated regions.
The mallee fowl averages about 15kg in weight and 60cm in length. The plumage is an intricately patterned, camouflage mix of black, tan, grey and brown. The mottled blend makes them almost invisible in their natural habitat. The underbelly and throat are white to grey. They have a dark beak. The legs are strong and powerful.
The mallee fowl is very shy. It rarely flies although it will roost overnight, flying up into low bushes or trees. It will also take short flights if threatened or pursued. Mostly it freezes in place when frightened, depending on its superb camouflage to save it.
It is thought that pairs bond for life. The male makes a 'booming' sound like the emu. Mallee fowls do not migrate as such but are sedentary. Males are very territorial around the nest.
The main diet of the mallee fowl is seeds from acacia and cassia shrubs. They also eat herbs, flowers and insects. They do not drink from surface water.
The mallee fowl it builds a mounded nest from vegetable matter. As the vegetation rots, heat is generated and eggs are incubated in the hot mound. The male continually adds to the nest or scrapes material away to regulate the heat. When a male mallee fowl begins to build his nest he first digs out a hole about a metre deep and four to five metres in diameter. Then he starts to fill the hole in with twigs, leaves and some dirt. He keeps adding material until he has a pile about 1 ½ metres above ground level.
The above image shows how well the mound blends into the scrubland.
The male's next task is to scratch out a pocket or egg chamber. When winter comes, the rain wets the organic matter. As it starts to rot, the material begins to ferment, creating heat much like a compost heap – which it essentially is. To prevent loss of heat and to help the decaying process, the male scratches dirt and sand over the nest. He may spend eleven months of the year tending to the nest.
The breeding season stretches from September to April. The female lays one egg at a time every three to seven days in the uncovered egg chamber. About 18 to 20 eggs is average, although up to 35 eggs may be laid. The number of eggs laid depends on the conditions and the rainfall. The egg weighs about 10% of the hen's weight. There is a wide range in incubation periods as much depends on the temperature of the mound.
The eggs are large, thin-shelled and pale pink in colour although by the time they are ready to hatch they will have turned a dark beige. As each egg is laid the male covers it over. He will open and close the mound, keeping the internal temperature to a constant 33 to 34oC. If there is insufficient heat being generated by the decomposition of the material, the mound will be opened to the sun.
The male probes the nest with his beak to check the temperature. It is usual for the same nest to be used each year and the mounds become bigger and bigger as they are added to each season.
The chicks have no egg-tooth and use their powerful feet to break out of the egg. They escape from the nest by lying on their backs and scratching their way free. The whole process of scratching and resting, scratching and resting, can take 2 to 15 hours. They break through the exterior with eyes and beaks closed, take a deep breath, open their eyes then freeze and rest for perhaps twenty minutes. Then they head for cover in the surrounding scrub. From that point they are on their own. The parent birds take no interest in them. Ninety-eight percent of chicks die, mainly from predators and starvation. If they do reach adulthood, they live for about thirty years.
Threats to the mallee fowl include competition for food from domestic and wild livestock such as sheep and rabbits and increased clearing of their habitat for agriculture. Predators include foxes and feral cats. The leaf letter so important in building their nests is destroyed through burning off and bushfires and increasing salinity of their areas is affecting vegetation growth.
Its classification in Australia varies from vulnerable to endangered depending on the authority. The International Union for Conservation of Nature (IUCN) classifies the mallee fowl as endangered.
The mallee prefers the same habitat as do agriculturalists and graziers ie good soils and good rainfall. They need large areas of unburnt mallee if they are to continue to survive.
The Victorian Malleefowl Recovery Group is based in Renmark, South Australia and encourages volunteers to help with collecting data from nest sites.
The Yongergnow Australian Malleefowl Centre in the town of Ongerup, near Gnowangerup, Western Australia, provides an opportunity to see the malleefowl in the wild. The Malleefowl Preservation Group conducts guided tours to observe active malleefowl nests.