Family Reed-warblers (Acrocephalidae)

Least Concern

Lesser Swamp-warbler (Acrocephalus gracilirostris)


French: Rousserolle à bec fin German: Kaprohrsänger Spanish: Carricero picofino

Calamoherpe gracilirostris


, 1864,

Liesbeek River, South Africa


Based on genetic data, may form a clade with A. rufescens, A. brevipennis, A. newtoni, A. sechellensis and A. rodericanus. Proposed race zuluensis (KwaZulu-Natal, in South Africa) synonymized with nominate, but has alternatively been lumped with leptorhynchus#R. Eight subspecies recognized.

Subspecies and Distribution
  • A. g. neglectus (Alexander, 1908) – N Nigeria and W Chad.
  • A. g. jacksoni (Neumann, 1901) – S Sudan S to E DRCongo, Uganda and W Kenya.
  • A. g. tsanae (Bannerman, 1937) – NW Ethiopia (L Tana).
  • A. g. parvus (G. A. Fischer & Reichenow, 1884) – highlands of SW Ethiopia S to Kenya, N Tanzania, Rwanda and Burundi.
  • A. g. leptorhynchus (Reichenow, 1879) – E Ethiopia, S Somalia and SE Kenya S to SE DRCongo, E & C Tanzania, SE Zambia, Malawi and N Zimbabwe.
  • A. g. cunenensis (E. J. O. Hartert, 1903) – SW Angola and N Namibia E to N Botswana, SW Zambia and W Zimbabwe.
  • A. g. winterbottomi (C. M. N. White, 1947) – E Angola E to N & NW Zambia and SW Tanzania.
  • A. g. gracilirostris (Hartlaub, 1864) – SE Zimbabwe and S Mozambique S to S Namibia and South Africa.
  • Descriptive notes

    17–18 cm; male average 16·1 g, female average 14·2 g. A fairly large, rather robust warbler with long bill, rounded wing, and strong legs and feet.... read more


    Song, usually from cover 1–2 m above water level, distinctive, consists of rich melodious... read more


    Reedbeds, reedmace (Typha), sedges and papyrus (Cyperus) in standing water of... read more

    Food and feeding

    Insects, also small frogs. Forages low down in reeds, often just above water; picks food items from low stems, water surface or floating... read more


    Laying Mar–Dec in Kenya and Tanzania, Jan–Aug in Malawi, Feb in Zambia, Aug–May in Zimbabwe, Aug, Nov and Feb in Botswana... read more



    Status and conservation

    Not globally threatened. Locally common; uncommon in S Sudan; scarce in lowlands of NW Lesotho; rare in W Chad. Common in Ethiopia, S Somalia, W & S Uganda, Rwanda,... read more

    Recommended citation

    Dyrcz, A. (2019). Lesser Swamp-warbler (Acrocephalus gracilirostris). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 25 April 2019).