Marsh Warbler | Acrocephalus palustris

Voice

The song is fast, fluent and extremely varied, a string of imitations of dozens of species, including sounds learned in Africa from bulbuls, cisticolas and weavers, among others, interspersed with its own nasal zee-chay notes and trills; in the region it sings freely from January to April, often also at night. The call is a hard chek and a grating chrr.

Identification

12–13 cm, with a rounded head, a fairly broad bill with a pale lower mandible and a short, slightly rounded tail. The upperparts are plain, cool olive-brown, without a rufous rump; the throat is clean white and the rest of the underparts off-white with a faint yellowish-buff wash. A short, faint supercilium is mainly in front of the eye. The primary projection is long, with eight visible, pale-tipped primaries; the legs are yellowish pink to pale brown, with pale claws. The sexes are alike; first-winter birds are warmer brown and closely resemble Common Reed Warbler. It moves shyly through dense bushes and rarely shows for long.

Confusion species

Common Reed Warbler Acrocephalus scirpaceus is warmer brown with a rufous rump, has a shorter primary projection and darker legs, and lives mainly in reeds; its song is a rhythmic, repetitive churring without the extensive mimicry. Without song the two often cannot be separated with certainty in the field. River Warbler Locustella fluviatilis has a finely streaked throat and long, pale-tipped undertail coverts and sings a sustained, insect-like reeling. Garden Warbler Sylvia borin is grey-brown with a short, stubby bill and an open, gentle face. Icterine Warbler Hippolais icterina is green and yellow with a pale wing panel.

Habitat

Dense bushes, creepers and rank herbage in savanna and woodland, in the understorey of riverine forest, forest edges and thickets on termite mounds, in gardens and neglected corners of farmland, often far from water; sometimes also in rank growth along marshes. It forages low to mid-level for insects and also takes berries.

Range and movements

Within the region mainly in the east: Malawi, eastern Zambia, Zimbabwe, Mozambique, eastern Botswana, and in South Africa in Limpopo, Mpumalanga, Gauteng, North West, KwaZulu-Natal, Eswatini, the eastern Free State and the Eastern Cape; scarce in northern Namibia and southern Angola. It breeds in Europe and western Asia and winters almost entirely in south-eastern Africa, after a long stopover in East Africa.

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

How and when to look

From December to April; listen in rank bushy areas and gardens for the continuous, fast song full of mimicry from a dense bush, for example in the Kruger National Park, around Pretoria or in the coastal forests of KwaZulu-Natal. A long ‘mixed chorus’ of African bird sounds from a single bush is often a Marsh Warbler; with patience it comes briefly to the edge and the white throat and pale legs can be seen.

Conservation status

Not threatened, with a large population that is expanding in the north and east of its breeding range. In the wintering range it tolerates disturbed vegetation; loss of thickets to clearance plays a local role.

Scientific name

Acrocephalus palustris | (Bechstein, 1798)

Bechstein described the species in 1798 as Motacilla s. Sylvia palustris; 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'. palustris is Latin for 'marshy'. The specimen the first description was based on came from Germany.