Sedge Warbler Acrocephalus schoenobaenus
Sedge warblers are easy to identify by sight. The broad white eyebrow is much bolder than in any other warbler in our region while the streaked upperparts are also a unique characteristic. They are a successful specie with a world-wide population in excess of 20 million birds.Large view
Because of their numbers and migrating habits, they are very popular birds with ringers at either end of their migration range. Ringers always harbour hope of getting a bird in their mist nets that had been ringed on the other end of the world.
Sedge Warblers are night migrants. The entire breeding population of sedge warblers winters in Africa south of the Sahara, leaving Europe from late August on. They leave their wintering grounds for their breeding ranges again in March, arriving from early in April. Large fat reserves are needed prior to departure. Some double their normal weight when fuelling up for migration. Lighter birds are forced to make the journey in several shorter parts. The migration is a remarkable achievement, entailing a flight of some 4000 kilometres. In the most favourable conditions, including tail winds, such a journey entails a flight time of between 75 and 95 hours and can be over in 14 to 21 days.
The sedge warbler mainly eats insects but some plant material like berries are taken, often low down in dense vegetation, usually near water. Feeding techniques include gleaning insects from vegetation while perched or sometimes the bird grabs airborne insects as it flies between perches. Sedge Warblers take advantage of the low temperatures around dusk and dawn when their prey is less mobile.
The Sedge Warbler is good mimic, and introduces phrases into its song in random, so it never sings the same song twice; those males with the widest range of phrases attract the most matings from females.
Its typical lifespan is two years, but the oldest bird on record is from a ring recovery at 7yr 11m.