Locustellidae

Locustellidae is a newly recognized family of small insectivorous songbirds ("warblers"), formerly placed in the Old World warbler "wastebin" family. It contains the grass warblers, grassbirds, and the Bradypterus "bush warblers". These birds occur mainly in Eurasia, Africa, and the Australian region. The family name is sometimes given as Megaluridae, but Locustellidae has priority.

The species are smallish birds with tails that are usually long and pointed; the scientific name of the genus Megalurus in fact means "the large-tailed one" in plain English. They are less wren-like than the typical shrub-warblers (Cettia) but like these drab brownish or buffy all over. They tend to be larger and slimmer than Cettia though, and many have bold dark streaks on wings and/or underside. Most live in scrubland and frequently hunt food by clambering through thick tangled growth or pursuing it on the ground; they are perhaps the most terrestrial of the "warblers". Very unusual for Passeriformes, beginning evolution towards flightlessness is seen in some taxa.

Among the "warbler and babbler" superfamily Sylvioidea, the Locustellidae are closest to the Malagasy warblers, another newly-recognized (and hitherto unnamed) family; the Black-capped Donacobius (Donacobius atricapillus) is an American relative derived from the same ancestral stock and not a wren as was long believed.