Common Grasshopper Warbler
Grasshopper Warbler
The grasshopper warbler ( Locustella naevia ) is a passerine bird of the genus Schwirle ( Locustella ) and the family of the warbler -like ( Sylviidae ). In Central Europe, this species is a widespread and locally common breeding and summer bird.
Description
The warbler is about 12 to 14 cm long and weighs 14 to 20 grams. The top is olive brown streaked and stained its underside yellowish white. The slender bird has reddish-brown legs and a wedge-shaped tail. Males and females have the same coloring. His singing sounds something like " sirrrr " and is reminiscent of a grasshopper, which is why he was formerly referred to as locusts singer. This song can also be heard at night, and even late August to early September, when most other songbirds are already silenced. The elusive warbler moves most like on the ground and avoid the flight.
Area of distribution and habitat
The breeding grounds of the Feldschwirls extends over the mittlerern widths from Western Europe until after Jennissej and the south east of the Altai Mountains. It occurs in Ireland and the UK, where the northern boundary runs through the north of Scotland, via Denmark, southern Norway and through the south of Finland. The southern limit of distribution extends from northern Spain through southern France to Romania and along the northern coast of the Black Sea to the Urals. The type is missing in the Alps and the Mediterranean.
The grasshopper warbler lives in open landscapes, wet meadows, swamps, bogs, on the river bank and in Heiden. It requires a minimum of twenty to thirty centimeters high herb layer and higher maintenance such as last year's perennials, shrubs individual or small trees. Soil moisture is of minor importance, since it also occurs in drier sites if they offer him the aforementioned conditions. Typical locations for nesting sites are large sedge swamps and moor grass, thinning, marbled with grassland reeds, light and moist forest sites or heavily weedy edges of forests and extensively used fields and pastures, meadows and ruderal areas.
In Central Europe, the long-distance migrant from April to September is observed. He has in tropical Africa its winter quarters. Check-out time and the pulling direction are innate.
Nutrition
The grasshopper warbler feeds on spiders, molluscs, insects and their larvae.
Reproduction
Sexual maturity occurs after one year. The main breeding season is May to July. Built from stalks, leaves and grass cup-shaped nest is well hidden on the ground in dense vegetation. The female lays 4 to 6 white purple speckled eggs. The eggs are 13 to 15 days warmed by both parents birds. The young birds stay 10 to 12 days in the nest. Both parents feed the birds. The adult birds fly the nest not directly, but land in the vicinity and approach taking advantage of ground cover of the nest. In Central Europe, second broods are rare and occur only in warm and dry years. In Britain and France two years broods are against the rule.
Stock
Short-term population fluctuations and local range shifts are typical of the grasshopper warbler, as he prefers areas with early successional stages and flood plains inhabited, the structure of which change rapidly. To high losses, it also comes in winter quarters. Main cause of local population decline are habitat destruction caused by drainage and groundwater drawdown followed by a rapid succession, the fragmentation of wetlands and the destruction of Hochstaudenfluren and riparian vegetation as well as an intensive agricultural use. Losses in the wintering sites mainly occur when there are extreme dry years in the Sahel region.
The German breeding bird population is estimated at 55000-120000 breeding pairs. In Austria 1200-1500 breeding pairs occur and live in Switzerland between 200 and 250 breeding pairs.