Early on in the breeding season, the male Forest Kingfisher explores nest sites or even begins preliminary digging at several sites. The pairs, which may share long-term monogamous bonds, both build the nest. Sometimes the nests are in tree cavities, earthbanks or roots of fallen trees; more often they are in arboreal termitaria (termite nests in trees), and they are usually 4 - 12 m above the ground. Each member of a pair flies straight at the nest site from several metres away, with their bills pointed forward like a bullet, chipping away some of the 'cement' with each impact. Eventually a nest chamber about 23 cm in diameter is formed at the end of a short, slightly sloping tunnel. Although the short sloping tunnel helps the nestlings eject their droppings some nests become very soiled. Both sexes, as well as helpers from the previous season, help in the incubationof the eggs as well as feeding the young. It is even possible that in warmer areas the heat of the sun and the termite nest during the day are sufficient for incubation. Both sexes defend the nest vigorously. There is agonistic (fighting) behaviour by the pair at the start of the breeding season defending their territory and during the breeding season the males spend much time perched on a branch, challenging persistently. The fledglings are fed by the adults for at least a month. In some areas there may be two broods per season, but this is rare in the sedentary Top End (far Northern Territory) population.