Wikipedia
Megalurus is a genus of passerine bird in the family Locustellidae. The genus was once placed in the Old World warbler " wastebin" family Sylviidae. The genus contains six species also known as the typical grassbirds. The genus is distributed from northern China and Japan, to India in the west, and Australia in the south, with most species being located wholly or partly in the tropics. The genus is also sometimes considered to include the genus Bowdleria, which holds the fernbirds of New Zealand. The most widespread species, the tawny grassbird, ranges from the Philippines to southern New South Wales, whereas the Fly River grassbird is restricted to swampland in the southern part of New Guinea. The natural habitat of the typical grassbirds is, as the name suggests, wet grasslands, swamps and other marshlands. Some species exist away from water in tall grasslands, heathlands, and forest clearings. Some species have adapted to the margins of rice fields and gardens.
The typical grassbirds are medium sized warblers with short rounded wings and long graduated tails, which are often worn. The plumage is brown overall, lighter on the belly and throat, with black streaks on the back. All species have a whitish line above the eye, and some have light streaking on the chest. They range in size from 13 to 28 cm in length and 14-56 g in weight. The genus is unique amongst the family and indeed the Old World warblers in possessing a vestigial wing claw.
Pairs or individual birds forage in dense vegetation. They are generally shy and seldom fly, instead foarge mostly by clambering up reeds and grasses, often quite agilely. When they do fly it is generally low to the ground and only for a few metres (although the Papuan grassbird will fly some distance when flushed). Insects form the major part of the diet, with insect larvae forming a large part of the diet of the tawny and marsh grassbirds. For the Papuan grassbird the seeds of grasses and sedges are important, and other foods taken by the genus include spiders and pine needles.
There is little information on the breeding of the Megalurus warblers. Some studies have suggested polygamy, while others have suggested monogamy is the most important breeding system. The nest is an open or partially open cup suspended in reeds. The clutch size is two to six eggs.