The diet of the red-backed kingfisher includes a variety of insects, particularly locusts and grasshoppers, but also beetles, praying mantises, ants and caterpillars (2). This kingfisher also feeds on a range of other invertebrates, including spiders, centipedes, scorpions and crustaceans, and it will even take vertebrates such as fish, frogs and tadpoles, lizards, snakes and mice (2) (3). Some red-backed kingfishers have been seen attacking nesting fairy martins (Hirundo ariel) and taking their eggs and chicks (2).
The red-backed kingfisher usually hunts from an exposed perch, swooping down to snatch its prey from the ground before carrying it back to a perch to be consumed (2) (3) (4). It also sometimes takes prey from the trunks of trees (2) (4) or from branches or woody debris (4).
In arid parts of central Australia, the red-backed kingfisher breeds opportunistically in response to rainfall, but in other parts of the continent it typically nests between August and March, with the exact timing depending on the location (2) (3). During courtship, this species calls and displays it distinctive red rump, and the male may offer food to the female (2).
The red-backed kingfisher typically excavates its nest in the vertical bank of a river or creek, or in an earth cliff, sandy bank, termite nest, or in earth among the roots of a fallen tree (2) (3). It will also occasionally use natural tree hollows (2). Both members of the breeding pair help excavate the nesting burrow, which can measures up to 120 centimetres in length (2) (3), although it usually averages around 28 centimetres in length and 6 centimetres in diameter. The burrow ends in a small nest chamber (2).
The female red-backed kingfisher lays a clutch of two to six eggs, and both adults take turns at incubating the eggs for 20 to 23 days. The young kingfishers leave the nest at around 26 to 30 days old (2) and the adults often go on to produce a second brood (2) (3), which they may start while the first brood of chicks is still being fed (2). The nests of the red-backed kingfisher are vulnerable to a range of predators, as well as to flooding caused by heavy rain (2).