Ratite And Flightless Bird Families

This group gathers taxon/Bird Families subcategory members that are themselves bird families belonging to the ratites, a group of large, flightless birds lacking the keeled breastbone that anchors the flight muscles of every flying bird, alongside other bird families that have independently lost the ability to fly. It spans the ostrich family of Africa, the largest living bird by weight, the family of the emu and cassowaries of Australia and New Guinea, and the kiwi family of New Zealand, unusually small-bodied for a ratite and unusual too for a highly developed sense of smell, uncommon among birds, used to locate food by scent while foraging at night. Every family gathered here descends from ancestors capable of flight, and the loss of flight across these lineages is now understood to have occurred independently several times rather than from one single flightless ancestor, a conclusion drawn from genetic evidence that overturned decades of assumption based on anatomy alone.