Common Grasshopper Warbler

The Common Grasshopper Warbler, scientifically known as Locustella naevia, is a medium-sized warbler measuring approximately 13 cm in length. It is characterized by a streaked brown back and a whitish grey underbelly, with the underparts being largely unstreaked except for the undertail coverts. Both sexes appear identical, a common trait among warblers, while juveniles exhibit a slightly yellower hue below.

Identification Tips

Adults display a pale olive-brown upper body with darker central streaks on each feather. The cheeks are a subtle grey, and the eyes are brown with a faint eye streak behind them. The beak's upper mandible is dark brown, contrasting with the yellowish-brown lower mandible. The wings are brown with paler edges, and the tail is reddish-brown, occasionally showing faint bars. The legs and feet are a pale yellowish-brown.

Habitat

This elusive bird favors short, dense vegetation and is often found near water. Its preferred habitats include the edges of fens, heaths, gorse thickets, young plantations, and felled woodlands.

Distribution

The Common Grasshopper Warbler breeds across temperate Europe and the western Palearctic, with its migratory patterns taking it to north and west Africa for the winter months.

Behaviour

Notoriously difficult to spot, the Common Grasshopper Warbler is known for its skulking nature, creeping through undergrowth and low foliage. It is more often heard than seen, especially when the male sings from a prominent position.

Song & Calls

The bird's song is a monotonous, mechanical, insect-like reeling, often performed at dawn or dusk. The alarm call is a distinctive ticking sound, transcribed as "twkit-twkit-twkit."

Breeding

The Common Grasshopper Warbler lays four to seven eggs in a nest situated on or near the ground within dense vegetation or grass tussocks. Both parents partake in nest-building and the care of their young.

Diet and Feeding

An insectivorous bird, the Common Grasshopper Warbler feeds on a variety of invertebrates, including flies, moths, beetles, aphids, dragonflies, mayflies, and their larvae, as well as spiders and woodlice.

Conservation Status

The IUCN Red List classifies the Common Grasshopper Warbler as Least Concern due to its large population and extensive range. However, habitat loss may be causing a decline in numbers, though not at a rate that currently warrants a higher risk category.