Blue-headed Wagtail (Motacilla flava)

[order] PASSERIFORMES | [family] Motacillidae | [latin] Motacilla flava | [UK] Blue-headed Wagtail | [FR] Bergeronnette printaniere | [DE] Schafstelze | [ES] Lavandera Boyera | [NL] Gele Kwikstaart

Subspecies

Physical charateristics

Smallest, most compact of west Palearctic wagtails, with form and silhouette more like pipit than any of the others.
Plumage of both adult and 1st-winter basically yellow below and on patterned edges of wing-feathers. Adult breeding male of the many races differ in head pattern: various combinations of yellow, white, bluish, grey, and black.
Sexes dissimilar in summer, less so in winter. Seasonal variation most marked on head of male only and chest.

Range

Eurasia : widespread

Habitat

Breeds in west Palearctic from lower middle to high latitudes, in arctic rundra and subarctic, boreal, temperate, steppe, and Mediterranean zones, mainly continental but marginally oceanic, largely on level or gently sloping lowlands.

Reproduction

Breeding starts May-June in Scandinavia, April-May in Britain and Ireland, April-June in Southern and Eastern Europe, April-May in North Africa.
Nest site is built on ground, in side of tuft of vegetation. Nest, cup of grass leaves and stems placed in shallow scrape, lined with hair, wool, or fur. Clutch size is 4-6 eggs, which are Incubated 11-13 days by both sexes.

Feeding habits

Small invertebrates. Three main foraging techniques, including use of high flight:
1) Picking, picks items from ground or water sufface while walking.
2) Run-picking, makes quick darting run at prey, picking it op either from surface or as it takes off.
3) Flycatching, makes short flight from ground or perch, catching prey in mid-air either in bill or by knocking it down with wings.
Occasionally takes insects from plants in hovering fllight, or flies low over water snatching insects fromsurface. Tail assists balance when turning rapidly in flight.

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). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to 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.

Migration

Most populations migratory, wintering Afrotropics, India, and south-east Asia. Egyptian race largely resident, and some parts of breeding range in north-west Africa and southern Spain occupied through the winter, with possibility that some individuals are resident.
Several factors make this a particularly well documented migrant: large populations; conspicuous (mostly diurnal) movement; use of huge communal roosts, both on migration and in winter, facilitating ringing; assumption by males of racially distinct breeding plumage shortly before spring migration. On the other hand, confusion can arise through racial intermediates and disjunct pattern of geographical variation. Precise wintering areas of the various races are not well established but in the main lie between south-east and south-west of respective breeding areas.

Movement broad-front in both spring and autumn, with numerous sightings of migrants at sea in all areas. Autumn passage in Switzerland has been noted as early as late July but main passage begins second half of August and peaks through September usually to end abruptly in early October, though individuals have been noted still passing in first third of November. At Straits of Gibraltar, passage extends from early August to early November peaking mid-September. Arrives in Afrotropics in late September, further south in October. Movement north in spring, after build-up of fat just south of Sahara, is also on broad front, starting in March and extending to early May. males reach breeding grounds before females; arrivals are from late March in south, west, and much of central Europe, from mid-April in Moscow area, and from early May or early June in Lapland.
Many records occur of birds resembling a particular race well outside that race?s normal range, but some (at least) of these are part of the species? normal variability and do not necessarily indicate vagrancy. Birds showing the characters of several races have been recorded in Britain, for example, mainly in spring and sometimes well outside their normal range: continental nominate flava occurs regularly and has bred occasionally.

Distribution map