Brush-turkey: The Rainforest Rake

Skyrail Nature Diary: October 2007

The Australian Brush-turkey (Alectura lathami) is the product of 130 million years of rainforest evolution: it’s a descendant of birds from the ancient super-continent, Gondwana.

The Brush-turkey is a member of theMegapodidae family, of which only three species still exist in Australia. The family name derives from these birds’ large feet and powerful legs, which they use to ‘rake’ leaf litter when foraging and building nests.

Brush-turkeys inhabit rainforests, dry scrubland and most of suburbia along Australia’s east coast, from Cape York Peninsula to the northern outreaches of Sydney. They are a protected species in Queensland and feeding by humans is discouraged, as it encourages dependence.

Growing up to 75cm in length, with a wingspan of 85cm, Brush-turkeys are the largest of Australia’s Megapode species. They are also easily recognisable, thanks to their blue-black plumage matched with a bright yellow wattle, red neck and head.

Commonly seen ‘raking’ the forest floor (or garden) with its large feet, the Brush-turkey has a unique fan-shaped tail. As well as being rather large for its body size, the Brush-turkey’s tail feathers grow on a vertical axis, which enables them to stay clear and clean of the leaf litter the bird is ‘racking’ backwards.

So why does a Brush-turkey ‘rake’ the forest floor? One reason is to build a nesting mound. Built by the male of the species, nesting mounds can reach up to two metres high and four metes wide: each mound can sometimes be used to incubate up to 50 eggs, often from several females.

Just how many different females use each nest is determined by the male’s success at keeping the nest’s temperature between the optimal incubation range of 33-38 degrees Celsius. The birds carefully monitor the nest’s temperature with heat sensors located in their beak; the male adds and removes leaf litter from the nest to keep the temperature constant, in accordance with fluctuations in outside temperature.

Further showcasing their affinity with all things meteorological, Brush-turkeys can predict storms long before the weather man, and subsequently build a conical cover atop the nest to keep their eggs dry.

Eggs often fall prey to burrowing animals such as goannas, but the male Brush-turkey will attempt to defend its nest with a classic dirty trick, kicking dirt into the eyes of would-be predators!

Brush-turkeys are solitary birds from the moment they hatch. Left to fend for themselves, chicks hatch fully-feathered and active: they can fly within one hour. Unfortunately, chicks often fall prey to foxes and domestic cats and dogs and the survival rate to adulthood can be as little as one in two hundred.