Bill straight, slight, culmen flat at the base; groove on each side of the upper mandible broad and shallow; neck and legs rather short, the back of the neck bare, but covered over by lengthened feathers from the sides. Head with a short crest. Scapulars and back-feathers normal, but the feathers of the upper breast much lengthened and concealing the lower breast, though not forming ornamental plumes.
Sexes different in plumage. Only 10 tail-feathers. This is a remarkable genus of small Bitterns, none of the ten species enumerated in Sharpe's Catalogue having a wing more than six inches long. The genus is found in most parts of the world; three species are Indian.
Key to the Species.
a. Tibia feathered to tibio-tarsal joint.
a1. Culmen about equal to mid-toe and claw……………………A. minuta, p. 400.
b1. Culmen longer than mid-toe and claw……………………A. sinensis, p. 401.
b. Tibia naked for some distance above joint……………………A. cinnamomea, p. 402.
The habits of all species of Ardetta are very similar. They hide in thick grass or reeds in marsh, dense swampy thickets, or high rice during the day, and can only be driven out by close beating; hence they are seldom seen. They climb about amongst bushes or thick reeds just as Purple Moorhens do, or like huge Grass-Warblers. They go out at dusk to feed at night on fish, frogs, water-insects, and worms, and about the sea-coast on crabs and other Crustacea. Some species occasionally feed during daylight.
The nest is a pad of grass or rush built on reeds with the tops bent down, or sometimes in a bush, or more frequently in a tussock of grass or a clump of reeds or bulrushes just above the water.