1. Breeding Season: Emus have a distinct breeding season, which typically occurs during the winter months in Australia (approximately May to October). During this period, males and females come together to find mates and form breeding pairs.
2. Courtship: Male emus engage in elaborate courtship displays to attract females. These displays involve deep booming calls, wing-flapping, and rhythmic stamping of their feet. The male will also present the female with nesting materials, such as twigs and grasses.
3. Nest Building: The female emu is responsible for building the nest. She selects a sheltered location, often under bushes or trees, and constructs a simple platform-like nest using available plant materials such as twigs, leaves, and grasses. The nest is typically around 10 to 20 centimeters deep and 50 to 100 centimeters in diameter.
4. Egg Laying: Once the nest is ready, the female emu begins laying eggs. Emus lay large, oval-shaped eggs that are dark green or bluish-green in color. They usually lay one egg at a time, but the clutch can consist of up to 20 eggs. The eggs are quite large, weighing around 500 to 600 grams each.
5. Incubation: The male emu is primarily responsible for incubating the eggs. He sits on the eggs constantly for about 8 weeks, protecting them from predators and maintaining a consistent temperature for proper development of the embryos. During this period, the male does not eat or drink but relies on his fat reserves for sustenance.
6. Hatching: After the incubation period, the eggs hatch, and the chicks emerge from the shells. The chicks are precocial, meaning they are born well-developed and mobile. They are covered in brown feathers with distinctive stripes that provide camouflage in the wild.
7. Parental Care: The male emu takes care of the chicks for a period of time, leading them to sources of food and water. However, the chicks are largely independent and are able to find food on their own. They grow rapidly and reach adulthood within about 12 to 18 months.
8. Polygamy: Male emus are polygynous, meaning they may mate with multiple females during a breeding season. However, they remain with one female at a time and engage in monogamous pair bonding for the period they share the nest and care for the eggs and chicks.
It's worth noting that emus can engage in same-sex breeding behaviors, particularly when there is a shortage of mates. Females can participate in these same-sex pairings, laying unfertilized eggs that are incubated and cared for in a similar manner as fertile eggs.
In summary, emus exhibit a combination of sexual reproduction, courtship behaviors, nest building, egg laying, incubation, and parental care during their reproductive process. Their breeding season and parental responsibilities are particularly notable aspects of their reproductive behavior.