Breeding birds: 260,000 territories
Family: Reed warblers
Sedge warblers have an olive-brown mantle and scapulars with dark brown streaks, and a cinnamon rump. On the upperwing the flight feathers are brown with pale buff edges, and the wing coverts are black with paler edges. The rounded tail is dark brown.
The belly is white, the flanks are pale rust and the rest of the underparts are cream or pale buff. On the underwing the axillaries and coverts are white with dark centres.
On the head the chin and throat are white, and the crown is dark with fine streaks. There is a conspicuous pale buff supercilium that extends from the upper base of the bill to the end of the ear coverts where it becomes broader. The lores are dark, and the cheeks and ear coverts are yellowish-brown. The bill has a dark brown upper mandible and yellow lower mandible with a pink base, the eyes are dark brown, and the legs and feet are grey-brown. Male and female sedge warblers are similar.
Juveniles are yellower than adults but with a similar pattern on the body and slight speckles or streaks on the breast. On the head there is a buff stripe in the centre of the crown.
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Sedge warblers are monogamous and breed between late April and mid-May and produce 1 or 2 broods a season. The nest in scrubby vegetation, marshes, bushes, and reedbeds near but not on water. It is usually supported on stems. The female builds the nest which is a deep cup-shaped structure made from loosely woven grass, stems, leaves, moss, and sedges, bound together with spider webs. It is lined with softer plant material, hair, and plant down.
Sedge warblers lay 5-6 smooth, glossy, pale green eggs even covered with fine olive specks and mottles, which are incubated by the female alone for 13-15 days. The male will help brood the chicks once they are hatched. Chicks leave the nest 11-12 days after hatching and fledge at 25-30 days.
Sedge warblers eat mainly insects including mayflies, dragonflies, grasshoppers, moths, and beetles. They will also eat worms, slugs, snails, and spiders. In autumn and winter it will supplement its diet with plant matter such as berries, fruit, buds, and flowers.
They usually feed at dawn and dusk in low, dense vegetation.
Sedge warblers arrive in the UK from their wintering grounds in sub-Saharan Africa and leave again in October. They can be found across most of the UK except the Highlands of Scotland. Look out for them in reedbeds and wetlands.
Britain's Birds
RSPB Handbook Of British Birds
Collins Bird Guide
Although the sedge warbler was first described by Carl Linnaeus in 1758, British ornithologists did not distinguish it from the reed warbler until the 18th century.
