Emus are Australia’s largest native birds. They rank as the second-largest living birds globally, surpassed only by ostriches. These flightless birds are an iconic part of the Australian landscape.
The Common Emu
The common emu, Dromaiius novaehollandiae, is the sole living species of emu. These birds stand between 1.6 and 1.9 meters (5.2 to 6.2 feet) tall and can weigh over 45 kilograms (100 pounds). Their shaggy, grey-brown feathers absorb solar radiation at the tips, while inner layers insulate the skin, helping them regulate body temperature.
Emus have long, powerful legs with three forward-facing toes, each with sharp claws, allowing them to run at nearly 50 kilometers per hour (30 miles per hour). Their wings are greatly reduced, measuring less than 20 centimeters (8 inches), and feature a small claw at the tip. Emus are classified as ratites, a group of flightless birds characterized by a flat breastbone, distinguishing them from flying birds. Common emus are widely distributed across mainland Australia, inhabiting most of the continent.
Habitat, Diet, and Behavior
Emus inhabit diverse environments across Australia, from woodlands and grasslands to semi-arid regions. They generally avoid heavily forested areas and dense human populations, but can be found near cities where native vegetation persists. Emus are omnivores, adapting their diet to available resources, including plants, fruits, seeds, grasses, insects, and small vertebrates. They also ingest pebbles, known as gastroliths, which assist their gizzard in grinding down food.
Emus are nomadic, moving across their range in response to climatic conditions and food and water availability. While often seen alone or in pairs outside the breeding season, they can form larger groups when food is abundant. Their communication includes booming, drumming, and grunting calls. Females produce a resonant booming sound using an inflatable neck sac, audible up to 2 kilometers away. They also engage in dust bathing to maintain their plumage.
During the breeding season, from December to January, female emus can lay multiple clutches of dark green eggs, ranging from 5 to 24 eggs per season. The male emu constructs a shallow ground nest lined with leaves, twigs, and grass. He then takes sole responsibility for incubating the eggs for 56 days, often not eating, drinking, or passing waste during this period, relying on stored body fat. After hatching, the cream-colored, striped chicks are cared for by the male for up to 18 months, learning to forage and navigate their environment.
Extinct Emu Species
Historically, several other emu species or subspecies existed, primarily on islands off the coast of southern Australia. These included dwarf emus from Kangaroo Island (Dromaiius novaehollandiae baudinianus), King Island (Dromaiius novaehollandiae minor), and the Tasmanian emu (Dromaiius novaehollandiae diemenensis). The King Island emu was approximately 44-45% smaller than the mainland emu, the Kangaroo Island emu about 25% smaller, and the Tasmanian emu approximately 10% smaller.
These island emu populations, isolated by rising sea levels after the last glacial maximum, were driven to extinction shortly after European settlement. Their demise was due to human activities, including over-hunting and habitat alteration through burning. The King Island emu was last seen in the wild around 1802, with the last captive specimens dying by 1822. The Kangaroo Island emu was hunted to extinction before 1827, and the Tasmanian emu became extinct around 1850.