This species resembles the preceding one so closely that even when examined in the hand, they are hard to distinguish. The general hue is, however, more greenish and less rufous than the Reed Warbler, and the legs are lighter in colour, being brownish flesh instead of yellowish brown. Alike as they are in appearance, their life history is very different. The Marsh Warbler is by no means confined to reeds, but may be found in osier beds, cornfields or coppices, being content, like the Sedge Warbler, with a very small extent of water. It sings its song, which is much sweeter and more melodious than that of the Reed Warbler, from the topmost sprays of its home, and the nests are never suspended in reeds but placed low down in some osier or small bush. The eggs are pale greenish white, blotched and marked with dark green, and are so characteristic that they cannot well be mistaken for those of any other species. It has a wide range in Europe, becoming scarcer towards the west, but in this country it is very local, and restricted as a breeding species to a few places in the south.

Very difficult to distinguish from the Reed Warbler, but the general hue is much greener, and the difference in the colour of the legs has already been noticed. Length 5·25 in.; wing 2·7 in.