The emu (Dromaius novaehollandiae) is the second-largest living bird globally, a powerful, flightless species endemic to Australia. Inquiries into its feeding habits often lead to confusion regarding its dietary classification. While foraging appears straightforward, the spectrum of what it consumes suggests a complex feeding strategy. This adaptability makes simple categorization challenging and requires a detailed look at its primary food sources versus occasional protein intake.
Primarily Plant-Based: The Herbivorous Core
The majority of the emu’s caloric intake is derived from plant matter, establishing its foundational diet as herbivorous. These birds are active foragers, consuming a wide array of native Australian vegetation, including the leaves and shoots of grasses and shrubs. This approach utilizes local resources as they become available across different environments.
Seeds, fruits, and flowers form a substantial part of their daily menu. They prefer seeds from species like Acacia and Casuarina. Emus also seek out fruits such as quandongs and various berries, which are ingested whole. Their diet shifts seasonally, often focusing on seeds and nuts during autumn when these resources are abundant.
The emu’s digestive system is equipped to handle this fibrous diet, notably lacking a crop common in many other bird species. To compensate, emus swallow small stones, known as gastroliths, which sit in the muscular gizzard. These stones function as a grinding tool, physically breaking down tough seeds and plant fibers for proper digestion.
Occasional Prey: Why Emus Are Not Strictly Herbivores
The complexity of the emu’s diet arises from its readiness to consume animal protein when the opportunity arises. This flexibility means that while the bulk of their food is plant-based, they are classified as omnivores. Animal matter consumption rarely exceeds five percent of their total diet but is important for meeting specific nutritional needs, particularly protein requirements.
The animal prey consists mainly of invertebrates, including a variety of insects and arthropods. They consume ants, beetles, spiders, grasshoppers, and the larvae of moths and butterflies. This protein boost is sought after during the warmer months and the breeding season, supporting the nutritional demands of the reproductive cycle.
Emus also consume small vertebrates, such as lizards, small snakes, and occasionally rodents like mice. This consumption highlights their adaptable nature, allowing them to thrive in Australia’s challenging environment. Their willingness to take advantage of any available food source, whether plant or animal, defines their feeding behavior as functionally omnivorous.