Aquatic Warbler

The Aquatic Warbler (Acrocephalus paludicola) is a medium-sized, Old World warbler known for its heavily streaked brown back and pale underparts with variable streaking. It has a distinctive flattened forehead, a strong and pointed bill, and a prominent whitish supercilium and crown stripe.

Identification Tips

Adults can be identified by their streaked appearance and the pale, spiky tail visible in flight. The supercilium and crown stripe are key features, with the latter being more pronounced than in similar species. Juveniles are less streaked on the breast. The sexes are identical, which is common among warblers.

Habitat

This species thrives in wet sedge beds with vegetation shorter than 30 cm, where it nests in low vegetation.

Distribution

Breeding primarily occurs in temperate eastern Europe and western Asia. The Aquatic Warbler is migratory, wintering in west Africa, particularly in the Djoudj National Bird Sanctuary, Senegal. Its migration route often leads it as far west as Great Britain and Ireland.

Behaviour

The Aquatic Warbler is highly promiscuous, with both males and females often having offspring with multiple partners. It is known for its south-westerly migration pattern.

Song & Calls

The song of the Aquatic Warbler is a fast, chattering "ja-ja-ja" interspersed with whistles typical of the Acrocephalidae family.

Breeding

The species lays 3–5 eggs per clutch, with the stronghold of breeding activity in the Polesie region of eastern Poland and south Belarus.

Similar Species

Juvenile Sedge Warblers may be confused with the Aquatic Warbler, but the latter's crown stripe and paler appearance in flight are distinguishing characteristics.

Diet and Feeding

Insectivorous by nature, the Aquatic Warbler also consumes small food items, including berries.

Conservation Status

The Aquatic Warbler is classified as Vulnerable, with habitat loss due to wetland drainage being the primary threat. Conservation efforts include habitat restoration and international cooperation under the Bonn Convention.

Conservation Methods

Habitat restoration is key, involving the removal of bushes, reeds, and trees, and ensuring proper water levels through hydraulic equipment.

Translocations

To combat declining genetic diversity, translocations have been carried out, such as the successful move of chicks from Belarus to the Žuvintas biosphere reserve in Lithuania.

Range and Population

The global population is estimated at 10,974 singing males, with the central European population being the largest but experiencing fluctuations. The species has seen declines in many regions, with some areas like Hungary not recording any birds since 2011.