[order] Passeriformes | [family] Sylviidae | [latin] Phylloscopus trochiloides | [UK] Greenish Warbler | [FR] Pouillot verdâtre | [DE] Grünlaubsänger | [ES] Mosquitero troquiloide | [IT] Luì verdastro | [NL] Grauwe Fitis

Grauwe Fitis determination

copyright: Keith Blomerley

Small, slim, graceful, and rather rakish Phylloscopus, light on the wing but neither as active nor as bold as Arctic Warbler. Plumage of western and northern form pale greyish-olive above, dull white below, with pale lower mandible, long yellowish-white supercilium (often turning up on nape), dark eye-stripe, usually short pale wing-bar on tips of outer greater coverts (in fresh plumage), and dusky legs.

Breeds in west Palearctic in middle latitudes, in continental warm, boreal, and temperate climates, mainly in lowlands in the north but in Caucasus from foothills to 3000 m. Although arboreal and tolerant of coniferous, broad-leaved, and mixed forest, prefers fringes, clearings, or open stands to denser growth, and favours crowns of such trees as birch and aspen scattered among spruces. Also occurs outside forest in copses, parks, thickets, and subalpine meadows.

Phylloscopus trochiloides (which here includes ‘Green Warbler' P. t. nitidus) is a widespread summer visitor to the Caucasus and north-eastern Europe, which accounts for less than a quarter of its global breeding range. Its European breeding population is extremely large (>12,000,000 pairs), and was stable between 1970-1990. The species probably remained stable overall during 1990-2000, with all populations either stable-as in the Russian stronghold-or increasing

Mostly small arthropods. Forages at all levels, from ground to canopy, picking items off vegetation; also captures insects in flight. Characteristically highly mobile, using hops and frequent short flights (also on ground), sometimes snatching insect from twig or leaf without pausing; flicks wings, perhaps to disturb prey.

This species has a large range, with an estimated global Extent of Occurrence of 10,000,000 km². It has a large global population, including an estimated 24,000,000-31,000,000 individuals in Europe (BirdLife International in prep.). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]

In Russia and Caucasus area laying begins first or second week June. Nest is located on ground in tall vegetation or low scrub, under stones, windfall, or tree roots, sometimes in crevices in banks, old walls, or tree stumps. Most nests well concealed and camouflaged. Nest is quite large and domed, with side entrance, constructed from grasses, plant fibres, moss, rootlets, and leaves, lined with finer material often including small amount of hair, fur, down, and feathers. Clutch size 3-7 eggs which are incubated 12-13 days. Young fledge 12-16 days after hatching.

Migratory; in east of range, some birds probably altitudinal migrants. West Palearctic population winters in Indian sub-continent from Himalayan foothills of Nepal and Sikkim south to southern India, east to Bangladesh and west to Uttar Pradesh and Madhya Pradesh (India). Autumn movement begins July. Western populations depart early: at Lake Ladoga, last records (all juveniles) early August, and reported in Moscow region until mid-August. First arrivals on Indian plains mid-August, with main passage to end of September. Spring migration begins early (from March) but is protracted. Reaches Estonia usually at end of May, but earlier (c. 19 May) in invasion years, and Sweden from late May. Regular west of breeding range in autumn, with late August to early September peak in Britain and Ireland.