Sedge warbler

The sedge warbler (Acrocephalus schoenobaunus) is a summer visitor to Europe, spending the winter months in tropical Africa. In the United Kingdom it can be found virtually anywhere except the Shetlands, and it is less likely to breed at higher latitudes. Its preferred habitat is thick vegetation, such as reedbeds and nettles, close to fresh water.

  

Sedge warblers leave for their winter quarters in September or October.

Appearance

The sedge warbler is 12-13 centimetres (5 inches) in length, and of plump build. Adult birds are brown above with darker streaks, these being thickest on the crown of the head. The rump is yellowy-brown. The underparts are mainly creamy white, but with shades of buff and yellow at the sides. A prominent feature is a broad creamy-white stripe above the eye on each side of the head. The tail is pointed and the legs greyish brown. Males and females are similar in appearance.

Behaviour

The sedge warbler has a jerky flight, usually low to the ground with the tail fanned. It will perch on bushes or creep through the undergrowth, sometimes sidling up stems. Its song is fast and varied, being less rhythmic than that of the reed warbler, comprising a mixture of musical and harsher notes. The sedge warbler will also mimic other birds.

Food for sedge warblers comprises insects, larvae, spiders and small molluscs, with berries being added to the diet as Autumn approaches.

Sedge warblers leave for their winter quarters in September or October.

Breeding

Sedge warblers return to their breeding grounds in late April, betraying their presence by their courting song flights comprising ascents with wings and tail outspread and shallow diving descents.

When paired, in May or June, sedge warblers build a fairly large nest in thick vegetation near, or sometimes directly above, water. The structure consists of stalks, moss and roots, lined with soft material such as animal hairs. Most of the nest building work is done by the female sedge warbler.

The clutch is of between four and seven eggs, incubated by the female alone for up to thirteen days. Both partners feed the nestlings, which are ready to leave the nest at between ten and thirteen days, after which they hide in the surrounding vegetation for another ten to fourteen days, still being fed by their parents. A second brood is sometimes raised.

© John Welford