The green malkoha or whistling yellowbill (Ceuthmochares australis), sometimes also known as green coucal, is an African bird in the cuckoo family. It is a notoriously shy bird and is seldom seen. Most of the bird is grey, but back, wings, and tail are green. It has a bright yellow beak and deep red eyes. Both sexes are similar, and it reaches a length of around 33 cm (13 in). It is similar in appearance to the blue malkoha or chattering yellowbill (Ceuthmochares aereus), and the two are sometimes considered subspecies of the same species. The blue malkoha, as the name suggests, is blue to bluish-green where the green malkoha is green.
The green malkoha is found in dense forests and vegetation, preferring warm temperate climate. Most of the time is spent hidden in thick vegetation in the canopy and subcanopy. It is rarely seen perched in the open, and it moves around by crawling along vines and creepers. It usually forage for food within its preferred dense habitat, and its main diet consists of invertebrates, smaller animals like frogs, and sometimes birds. Fruits, seeds, and leaves are also included in the diet.
The green malkoha is a monogamous solitary nester, and not a brood parasite, which is common among other cuckoos. Breeding season is in the period October-December. Two to four eggs are laid in a nest made up of twigs, and plant debris. The nest will be lined with fresh leaves during the incubation period. The nest is hidden in thick vegetation and often situated high up in tall trees. Both adults take part in raising the young.