All species › Cassowaries and emu
Cassowaries and emu | Casuariiformes
Kasuarisachtigen | Casuariformes
Large flightless birds without a keel on the breastbone, so there is nothing for flight muscles to attach to; the wing is reduced to a stump and the whole weight rests on two heavy three-toed legs. The feathers lack the hooklets that elsewhere make a closed vane, and because two equal feathers grow from each shaft the plumage hangs over the body like a coarse, hair-like curtain. Throat and neck carry bare coloured skin, and in the cassowaries wattles as well; the call is a deep boom, part of it below the limit of human hearing, which carries through dense forest where higher notes break up. The male incubates and raises the young alone; the female lays and moves on.
Families in this order
- Emu and cassowaries | Casuariidae2 speciesThe cassowary carries a helmet of horn over spongy bone on its head, whose function is still unsettled: a role in pushing branches aside has been suggested, a role in shedding heat, and a role in carrying the very low boom with which the birds find each other in dense forest. The inner toe bears a straight ten-centimetre claw with which a cornered bird kicks forward. Both species in this family are fruit-eaters that swallow large seeds whole and pass them undamaged kilometres away; for a range of rainforest trees that is the only way the seed travels. The Emu lives on seeds, shoots and insects and follows the rain through the interior, sometimes for hundreds of kilometres. In both species the female lays a clutch of large green eggs and then departs; the male incubates for eight weeks, barely rising in that time and eating and drinking almost nothing.