Description:

The elephant emu (Dinodromius dinodromius) is a browsing ratite species that lives in Australia. These birds evolved from the modern-day emu (Dromaius novaehollandiae) that survived the Holocene-Anthropocene extinction event. These ratites adapted and diversified into several different forms. This species evolved to eat the leaves high up on trees. They are taller than their ancestor, with a height of 2.1 to 2.9 meters. This increased height allows them to reach vegetation that is out of reach from other animals. They are also hefty birds, weighing 275 to 650 kilograms. Males are generally smaller than females. They also have an exposed section of blue skin on their neck, which helps to control their internal body temperature. They also have a beak that has evolved to pick small leaves and fruit from trees. These birds are drab brown with several black feathers on the head. They are also long-lived birds, living up to 40 years in the wild and 60 years in captivity.

Distribution:

These birds inhabit Australia except for the dune deserts and dense rainforests. This wide range is likely due to their adaptability and the diverse range of food they consume. Various subspecies also inhabit islands of the coast of Australia.

Diet:

The majority of their diet consists of leaves, fruits, grasses, seeds, and various other vegetation. They will also eat insects, other arthropods, and rarely small vertebrates. Typically, baby elephant emus eat more animals compared to plants. These birds will move on from their insectivorous/carnivorous to herbivorous ones. Adults will still eat carrion and bones to gain calcium from them. They will also eat small pebbles and rocks to use as gastroliths or gizzard stones, which allows them to break down bones and tough plant matter.

Mating and Reproduction:

These birds are seasonally monogamous, which means they pair up with one mate for a season. These emus pair up during the end of the summer season. During the pairing season, males will produce large bellowing noises to attract females. When a female comes into proximity of them, the male will dance by moving their head from high to low and stomping the ground. The female will then decide whether to pair with the male for the breeding. Once this pairing period ends, mating will begin at the end of the summer season, which is right before the wet season. They typically lay at most four eggs, which are about 20 to 24 centimeters in length with 10 centimeter diameters. The eggs are kept in a nest of sticks, leaves, grasses, and various other materials until they hatch. The father and mother will take turns brooding the eggs. This process allows them to acquire food while waiting for the eggs to hatch. Once the eggs hatch, the father is responsible for raising and defending the chicks until they reach sexual maturity. This process can take up to two and a half eggs, so the father spends most of his life raising them.

Subspecies:

Several different subspecies live on offshore islands near the coast of Australia. These subspecies tend to be smaller than the mainland subspecies Dinodromius dinodromius continentemus. Three island subspecies are currently alive: D. d. bayes, D. d. ventulus, and D. d. cavais. These subspecies inhabit the northwestern Bayes Island, the Breeze Island Chain near the southeastern coast, and the southwestern Hollow Cave Islands. All three subspecies have shrunk in size (all of them shorter than 1.5 meters) due to the island conditions. Due to the lack of predators on these islands, they are far less skittish around people when compared to their mainland relatives.