The Australasian grebe can often be found roosting on the water in pairs, families or small groups (3). This species is able to swim both high and low in the water (4) and is a frequent diver (5), often disappearing underwater in search of food (4). When disturbed, it may lurk within vegetation, with nothing but its head poking above the surface (5).
The Australasian grebe’s diet is relatively varied, and includes small fish, spiders, aquatic insects and their larvae, crustaceans, and freshwater molluscs such as snails (2) (3) (9). However, this small bird is also known to feed on vegetable matter, including grass seeds (3) (9), and has even been recorded consuming frogs (3). Commonly foraging near submerged or floating vegetation or at the edges of reed beds (3), the Australasian grebe catches its prey either through surface chases or by performing deep dives. This species is also known to associate with other waterbirds, capturing the insects and other invertebrates that these birds flush out (2).
It is thought that the Australasian grebe’s breeding season is stimulated by flooding (3), and it is known to be prolonged as a result of opportunistic breeding on temporary wetlands. However, on permanent waters of south-eastern Australia, this species breeds primarily in the spring (2) (3), with egg laying occurring between September and November (2).
The Australasian grebe is a territorial species that breeds in solitary pairs (2) (3). Nesting occurs in the water, usually among submerged, emergent or overhanging vegetation (3), and the nest consists of a small, floating platform made from plant material. The female Australasian grebe usually produces four or five eggs per clutch (2) (3), and the eggs are laid within a small depression in the centre of the nest (3). The eggs are then incubated by both the male and the female Australasian grebe for a period of about 23 days (2) (3). By eight weeks old, the chicks are independent from the adults, although it is not known at what age the young birds become capable of flight (3). A female Australasian grebe can produce two or three broods per breeding season (2).