River Warbler (Locustella fluviatilis)

River Warbler

[order] PASSERIFORMES | [family] Locustellidae | [latin] Locustella fluviatilis | [UK] River Warbler | [FR] Locustelle fluviatile | [DE] Schlagschwirl | [ES] Buscarla Fluvial | [NL] Krekelzanger

Subspecies

Monotypic species

Physical charateristics

Small to medium-sized rather long-tailed, lithe, dull dark brown warbler, unmarked but for mottled throat, chest, and under tail-coverts and warmer tone on upper tail-coverts and tail. Plumage may have gey, olive, or umber tone. Sexes slightly different, little seasonal variation.

Listen to the sound of River Warbler

[audio:http://www.aviflevoland.nl/sounddb/R/River Warbler.mp3]

Copyright remark: Most sounds derived from xeno-canto

wingspan min.: 19 cm wingspan max.: 22 cm
size min.: 14 cm size max.: 16 cm
incubation min.: 15 days incubation max.: 15 days
fledging min.: 14 days fledging max.: 15 days
broods: 1   eggs min.: 4  
      eggs max.: 7  

Range

Eurasia : Central

Habitat

Breeds in upper middle and middle latitude s of warm continental boreal, temperate, and stepes zones of west-central Palearcic. Requires ample stands of very dense but rarely tall vegetation, growing on shady bare soils, accessible to foraging and easy, concealed movement. Such cover may include thickets of grass and nettles among young growth of hazel, dogwoom, alder, birch, hornbeam, willow, and other trees characteristic of moist carr woodland and of floodlands, backwaters, damp fores clearings, bottmlands, bogs, sedge marshes, and even parks sometimes within cities.

Reproduction

Breeds May-July in Eastern Europe. Nest site is built on or within 30 cm of ground in thick vegetation or at base of bush. Nest, loose cup of grass stems and leaves, lined with finer grass and hair. 5-6 eggs are laid, incubation 11-12 days, by female only.

Feeding habits

Flying and non-flying arthropods, especially Bugs, True Flies, small beetles, and spiders. Food obtained in dense herbaceous and bushy vegetation, by running about in grassy vegetation, and among fallen leaves of alder and nettles on in woods along rivers and streams. Prey tamen directly from plants and ground, rarely in the air.

Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Locustella fluviatilis is a widespread summer visitor to central and eastern Europe,
which constitutes >75% of its global breeding range. Its European breeding population
is very large (>1,900,000 pairs), and was stable between 1970-1990. The species
remained stable overall during 1990-2000, with the stronghold population in Russia
probably stable, and stable or increasing trends across much of the rest of Europe.
River Warbler status Least Concern

Migration

Migratory. Winter quarters not well known, but lie from northern South Africa north to Zambia, Mozambique, and perhaps extreme south of Malawi. Migration very inconspicuous, perhaps due (in autumn) as much to skulking behaviour as to long-distance flights, as span of dates suggests passage protracted; no staging posts known within Europe. General direction is via east Mediterranean and Levant, requiring south-east heading for western breeders, and progressively more westerly heading for eastern breeders.

Distribution map

River Warbler distribution range map

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