Families overview for this order
Division into two subfamilies has been proposed#R: Heliopais and Podica in Podicinae; and Heliornis in Heliornithinae.
- Medium-sized largely aquatic birds, with brightly coloured lobed toes.
- Thickly vegetated margins of rivers, lakes and swamps.
- Small to medium-sized terrestrial, marsh and aquatic birds, with short and deep to long and slender bill, moderately long neck, broad wings, short, soft tail and strong legs.
- Worldwide, except for polar regions and waterless deserts; widely distributed on oceanic islands.
- Many types of wetland; also grassland, forest and dense scrub.
- Medium-sized terrestrial birds, with fairly long neck and legs, short, stout bill and hump-backed appearance.
- N South America.
- Dense tropical forest.
Shows morphological affinities with Gruidae and Rallidae. DNA studies suggested possible grouping with finfoots in family Heliornithidae, but more recent molecular analyses indicate that it is probably sister-family to Gruidae#R.
- Large brown, rail-like or ibis-like wading birds, with long bill, neck and legs.
- Tropical and subtropical parts of the Americas.
- Mainly in and around freshwater wetlands; also mangroves, and occasionally much drier zones.
Probably sister-family to Aramidae#R.
- Large, graceful wading and terrestrial birds, with long neck and legs, and mainly grey or white plumage.
- All regions except Antarctic, but only marginal in Neotropical; greatest diversity of genera in Africa, of species in Asia.
- Wide expanses of shallow wetlands and grasslands from the Arctic to the tropics.