Great Reed Warbler

The Great Reed Warbler is the giant of the Acrocephalus warblers, noticeably larger and more robust than the familiar Eurasian Reed Warbler, with a heavier build, a stouter bill, and a more prominent pale supercilium. Plumage is plain warm brown above and paler buff below, similar in tone to its smaller relative but on a considerably larger frame.

Its size and heavy bill give it a slightly thrush-like impression at first glance, and it often perches conspicuously atop a reed stem, bending it under its weight, unlike the more furtive foraging typical of smaller reed warblers.

The species is renowned for its extremely loud, far-carrying, harsh song, among the loudest and most distinctive of any European songbird, which can be heard well beyond the reedbed itself.

Key field marks

• Notably large size for an Acrocephalus warbler, close to a small thrush
• Heavy, robust bill
• Plain brown upperparts with a more prominent pale supercilium than Reed Warbler
• Pale buffy-white underparts
• Often perches conspicuously atop swaying reed stems

Similar species

• Eurasian Reed Warbler: much smaller and slimmer with a finer bill and a far quieter, more even song.
• Sedge Warbler: smaller, streaked above, with a different, scratchier song.
• Thrush species: superficially similar in bulk but with completely different plumage patterns and a thicker, more generalist bill shape.

Great Reed Warblers breed across much of continental Europe and western Asia, though they are absent as breeders from Britain and Ireland, favouring extensive, tall reedbeds around lakes, slow rivers, and large marshes, generally requiring larger stands of reed than the Eurasian Reed Warbler.

They are long-distance migrants, wintering in sub-Saharan Africa, and their loud song makes them one of the easiest reedbed species to detect even where dense vegetation obscures the birds themselves.

The species has declined in parts of western Europe linked to loss and degradation of large reedbed habitats.

Voice

The song is loud, deep, and harsh, a slow, grating, croaking sequence often rendered as "karra-karra-kreck-kreck-kreck," delivered at high volume and carrying well across open reedbed. It is one of the most distinctive and far-reaching songs among European songbirds.

Feeding

Great Reed Warblers feed on insects and spiders gleaned from reeds and waterside vegetation, and are also known to take small vertebrates such as tadpoles and occasionally small fish, a broader diet than most warblers.

Nesting and breeding

The nest is a large, deep cup woven around several reed stems, similar in construction to the Reed Warbler's but larger. Clutches typically contain four to six eggs.