Mallee Fowl

The bird with the built-in thermometer

The Mallee Fowl (Leipoa ocellata) is a ground-dwelling Australian bird which looks rather like a large pheasant. It builds its own compost heap to keep its eggs warm!

In the autumn, the male Mallee Fowl digs a hole up to 5m wide and 1m deep. During the winter, they fill it with twigs and leaves, scooping a hollow in the top in which the female will lay her eggs. In spring when it rains, the vegetation in the nest gets thoroughly soaked and begins to rot. Like a compost heap, the rotting vegetation heats up.

The male covers the mound with sand to keep it warm. When the female is ready, she lays her egg on top of the mound, and the male covers it up again with sand. Throughout the summer, the female lays up to 35 eggs, one at a time, on the nest mound.

Testing the temperature
Throughout this time, the male keeps testing the temperature of the mound by dipping his beak into it. He makes sure it doesn't get too hot or too cold, by adding more sand if it is cooling down, or opening up the mound if it is getting too hot. He cleverly keeps the temperature of his ingenious incubator near a perfect 34 degrees C.

When the chicks hatch, one at a time, they dig their own way out of the mound and run off to find their own food.