Great Reed Warbler | Acrocephalus arundinaceus

Voice

A loud, slow and harsh song of grating and croaking notes, each repeated two or three times, karra-karra-keet-keet-gurk-gurk, like a coarser, frog-like Common Reed Warbler. In the wintering area it sings mainly in the early morning and in the weeks before departure. Calls a hard chak and a rattling kerr.

Identification

19–20 cm, almost thrush-sized, with a heavy, long bill, a flat head and a strong, fairly long tail. Upperparts warm olive-brown with a more rufous rump, underparts dull white with a warm buff breast and flanks. A distinct pale supercilium reaches behind the eye, with a dark eye-stripe below it. The primary projection is long, as in a long-distance migrant. The legs are pale greyish-brown to pinkish-brown and the lower mandible is pink. The sexes are alike; first-year birds are warmer and fresher in the austral summer than worn adults, which moult in Africa.

Confusion species

Greater Swamp Warbler Acrocephalus rufescens is darker and more uniform, without an obvious supercilium and with dark legs; it is a resident of northern papyrus swamps with a bubbling song. Lesser Swamp Warbler Acrocephalus gracilirostris is smaller, with a white throat and dark legs. Common Reed Warbler Acrocephalus scirpaceus and Marsh Warbler Acrocephalus palustris are much smaller, with a finer bill. Basra Reed Warbler Acrocephalus griseldis is smaller and greyer, with a long, thin bill, and only exceptionally reaches the region. Size, bill and the loud, grating song are the best features.

Habitat

In the wintering area less tied to reeds than in Europe: reedbeds and rank growth along rivers and dams, but also dense bushes and thickets along rivers, in damp hollows and even in woodland far from water. It forages rather heavily for large insects, spiders and at times small frogs, and also eats berries before migration.

Range and movements

Within the region mainly in the north and east: Angola, Zambia, Malawi, Zimbabwe, Mozambique, northern and eastern Botswana, northern Namibia and, in South Africa, chiefly Limpopo, Mpumalanga, Gauteng, North West and KwaZulu-Natal; scarce to rare further south and west. It breeds from north-west Africa and Europe to Central Asia and winters in sub-Saharan Africa.

• Resident
• Summer visitor (c. Oct–Mar)
• Passage (Mar–Apr, Oct–Nov)
• dark = core range, pale = thinly spread

How and when to look

Best from December to March; listen in the morning at reedbeds and riverine thickets along rivers and dams for the loud, grating song, for example in the Kruger National Park, at Pongola, or along the Zambezi in Zimbabwe and Zambia. A singing bird often perches high in a bush or on a reed plume and is then fairly easy to see.

Conservation status

Not threatened. The European breeding population has declined markedly in the west of the range since the twentieth century, mainly through the loss of extensive reedbeds, but is large and stable elsewhere. No clear threats are known in the wintering area.

Scientific name

Acrocephalus arundinaceus | (Linnaeus, 1758)

Linnaeus described the species in 1758 as Turdus arundinaceus; because it was later moved to another genus, the author and year stand in brackets. The genus Acrocephalus was introduced in 1811 by Naumann & Naumann. Acrocephalus is Greek, from akros 'topmost, pointed' and kephalē 'head'; the Naumanns, who introduced the genus, called these birds Spitzkopf 'pointed head', so they read akros as 'pointed'. arundinaceus is Latin for 'like a reed', from arundo, genitive arundinis, 'reed'. The specimen the first description was based on came from northern Europe.