The emu (Dromaius novaehollandiae) is the second-largest living bird species, a flightless native of Australia. Although its diet appears primarily vegetative, the emu is not a herbivore. This large bird is an omnivore, relying on a varied mix of both plant and animal matter. This flexibility allows the emu to thrive across Australia’s diverse and often harsh environments.
Defining the Emu’s Diet Classification
An omnivore is defined biologically as an animal that includes both plant and animal material in its natural diet. This classification differs from a herbivore, which feeds exclusively on plants, and a carnivore. The emu’s digestive system has evolved to efficiently process a wide range of food types, solidifying its place as an opportunistic omnivore.
Its diet is adaptive, shifting based on what is seasonally available in its immediate environment. This reliance on environmental opportunity is a successful survival mechanism in the unpredictable Australian landscape. Although the bulk of the emu’s caloric intake may come from plants, the consistent consumption of protein sources prevents a purely herbivorous designation.
Primary Plant-Based Consumption
The majority of the emu’s foraging efforts are directed toward consuming a broad spectrum of plant material found across the continent. They feed extensively on seeds from native species like Acacia and Casuarina, which often form a staple part of their diet. Emus are significant seed dispersers, consuming a variety of fruits, flowers, and soft shoots when they are available.
Their diet also includes native grasses, roots, and underground tubers. The foraging strategy is highly seasonal, with emus actively seeking out fresh grass shoots after rains or switching to fruits like the quandong in springtime. To process this tough, fibrous plant matter efficiently, emus swallow small, abrasive stones called gastroliths. These stones are held in the bird’s muscular gizzard to grind food in place of teeth.
Supplementary Protein Sources
The inclusion of animal matter in the emu’s diet definitively establishes its omnivorous status. This component is particularly important for providing the necessary protein required for growth and reproduction. Emus actively hunt and consume a wide array of invertebrates, which often make up 15 to 20 percent of their total caloric intake.
Invertebrate Sources
Emus actively seek protein-rich meals, especially during the breeding season to support egg production and chick rearing. Common invertebrate targets include:
- Grasshoppers
- Crickets
- Beetles
- Caterpillars
- Spiders
Emus also opportunistically consume small vertebrates, such as lizards or rodents. This protein supplementation is a deliberate nutritional choice that sustains the bird’s large body mass and provides energy for its nomadic lifestyle.