The world of birds contains extremes of size, including towering, flightless species known as ratites. These large, ground-dwelling birds are known for their immense stature. While the largest bird is well-known, identifying the next in line requires a specific metric to determine the second largest avian giant.
Unveiling the Second Largest Bird
The second largest living bird in the world, measured by height, is the Emu (Dromaius novaehollandiae). This flightless bird is native and endemic to the Australian continent, where it is the tallest species. Adult Emus consistently reach a height of up to 1.9 meters (6.2 feet), placing them second only to the African Ostrich, which can reach 2.8 meters.
Height is the necessary metric for this ranking. Other large ratites, such as the Southern Cassowary, can be heavier than the Emu, sometimes exceeding 40 kilograms. However, the Cassowary stands shorter, securing the Emu’s position as the second tallest bird globally. Female Emus are typically slightly larger and heavier than males.
Physical Characteristics and Unique Adaptations
The Emu’s body is covered in shaggy, dark gray-brown plumage that provides insulation from the Australian sun. Unlike the streamlined feathers of flying birds, Emu feathers are double-shafted, meaning two feathers grow from a single follicle. This gives them a loose, hair-like appearance and helps regulate body temperature by trapping air, preventing overheating.
While the wings are greatly reduced and vestigial, the Emu’s powerful legs are built for speed and defense. Their long legs feature three forward-facing toes, maximizing running efficiency. They can sustain speeds of up to 48 kilometers per hour (30 mph), which is essential for escaping predators. The muscular legs are also their primary defensive weapon, capable of delivering powerful kicks with long, sharp claws. The Emu has a small, black bill adapted for grazing, and sparse neck feathers reveal pale blue skin beneath.
Habitat, Diet, and Social Behavior
Emus are nomadic birds found across most of the Australian mainland, inhabiting a wide variety of environments from savanna woodlands to sclerophyll forests. They are highly adaptable but generally avoid dense rainforests and extremely arid regions. Their movements are dictated by the availability of food and water, sometimes traveling hundreds of kilometers in search of resources.
The Emu is an omnivore, with a diet that changes seasonally to include various plants and small animals. They forage for seeds, fruits, grasses, and flowers, supplementing this with insects and occasionally small vertebrates. To aid in digestion, Emus swallow small stones, known as gastroliths, which sit in the gizzard and grind down the tough plant material they consume.
Socially, Emus are generally solitary outside of the breeding season, though they may temporarily form large flocks when congregating at a common food source. The breeding cycle features a parental role reversal. The female courts the male and may mate with several partners, laying multiple clutches of eggs. The male builds a nest on the ground, takes sole responsibility for incubating the dark green eggs for eight weeks, and raises the striped chicks for up to seven months.