Order: GruiformesFamily: Heliornithidae  Heliornithidae is a small family of tropical birds with webbed lobes on their feet similar to those of grebes and coots. There are 3 species worldwide and 1 species which occurs in the Democratic Republic of Congo. Order: OtidiformesFamily: Otididae  Bustards are large terrestrial birds mainly associated with dry open country and steppes in the Old World. They are omnivorous and nest on the ground. They walk steadily on strong legs and big toes, pecking for food as they go. They have long broad wings with "fingered" wingtips and striking patterns in flight. Many have interesting mating displays. There are 7 species which have been recorded in South Sudan. Order: CharadriiformesFamily: Turnicidae  The buttonquails are small, drab, running birds which resemble the true quails. The female is the brighter of the sexes and initiates courtship. The male incubates the eggs and tends the young. Order: CharadriiformesFamily: Jacanidae  The jacanas are a group of tropical waders in the family Jacanidae. They are found throughout the tropics. They are identifiable by their huge feet and claws which enable them to walk on floating vegetation in the shallow lakes that are their preferred habitat. Order: CharadriiformesFamily: Rostratulidae  Painted-snipe are short-legged, long-billed birds similar in shape to the true snipes, but more brightly coloured. Order: CharadriiformesFamily: Recurvirostridae  Recurvirostridae is a family of large wading birds, which includes the avocets and stilts. The avocets have long legs and long up-curved bills. The stilts have extremely long legs and long, thin, straight bills. There are 2 species which have been recorded in South Sudan. Order: CharadriiformesFamily: Burhinidae  The thick-knees are a group of largely tropical waders in the family Burhinidae. They are found worldwide within the tropical zone, with some species also breeding in temperate Europe and Australia. They are medium to large waders with strong black or yellow-black bills, large yellow eyes and cryptic plumage. Despite being classed as waders, most species have a preference for arid or semi-arid habitats. There are 3 species which have been recorded in South Sudan.