Skylark (Alauda arvensis)
[order] Passeriformes | [family] Alaudidae | [latin] Alauda arvensis | [UK] Sky Lark | [FR] Alouette des champs | [DE] Feldlerche | [ES] Alondra de Eurasia | [IT] Allodola | [NL] Veldleeuwerik
spanwidth min.: 30 cm
spanwidth max.: 36 cm
size min.: 18 cm
size max.: 19 cm
incubation min.: 11 days
incubation max.: 13 days
fledging min.: 18 days
fledging max.: 20 days
eggs min.: 6
It is a small to medium-sized ground dwelling species. Overall it is basically streaky brown above and white below with a gorget of fine streaks. In flight it shows a thin, diffuse off-white trailing edge to the wing and white sides to the tail. The head has a crest but this is often held flat, rendering it invisible. It is unlikely to be seen perched other than on a fence post, preferring to scuttle around on the ground. Its most striking feature is its melodious warbling song during breeding season, delivered for continuous periods of 3 to 15 minutes at a fast pace. The male sometimes sings from a perch, but usually in typical song-flight, climbing steadily higher on fluttering wings until eventually staying in one spot, hovering at 50 to 100m.
Prefers open grassy terrain without any substantive tree cover. Ideal vegetation height for nesting is about 15 to 40cm, with very short or sparse vegetation nearby for feeding. High density habitats are typically sand dunes, marginal uplands and uplands with predominantly unimproved grasslands. Also present in lower densities throughout lowland farmland, occurring in arable crops and a variety of grassland habitats. During winter, large flocks occur in stubble fields, root crops and permanent pastures.
Alauda arvensis is a widespread breeder across most of Europe, which accounts for less than half of its global breeding range. Its European breeding population is extremely large (>40,000,000 pairs), but underwent a large decline between 1970-1990. Although declines continued in many western European countries during 1990-2000, key eastern populations remained stable, and the species probably declined only slightly overall. Nevertheless, its population size remains far below the level that preceded its decline.
This lark is very common and inhabits a major part of Europe and Asia. It is breeding in all regions of the European Union, where its population amount to 15-20 million breeding pairs (EBCC Atlas of European Breeding Birds). Originally a bird of the steppes or similar open habitats, it has become adapted to cultivation. Since a few decades it undergoes a strong decrease following more general use of pesticides and changing agricultural practices.
The skylark needs abundant insect food during the summer, but is mainly granivorous in winter.
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 79,000,000-160,000,000 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]
Pairs form in February, leaving large winter flocks to establish territory, generally the same year after year. At this time, males start their flight displays, climbing from the ground in spiral, and singing strongly. Once at high elevation, male descends in spiral, alternating wing beats and glides, always singing. When arrived at some lower elevation, it "falls" to the ground as a stone. On the ground it performs other displays, walking around female with erect crest, dropped wings and fanned tail. Courtship displays reach a peak in March and April, and much more after a strong rain, which remains a riddle. Skylark is territorial during breeding season. The bird performs its displays on the ground, with ruffled feathers, erect crest and some threatening actions such as fluttering off the ground with half open wings, and also with aerial displays such as series of upwards glides with some fluttering towards the intruder.
Breeding begins in late April through to July, with two or three clutches of 3 to 5 eggs. The nest is a shallow cup of grasses and sometimes hair, often in a slight depression in the ground, sometimes sheltered by a tuft of grass. Incubation lasts 11 days. Nestlings leave nest at 9 to 10 days, but are not able to fly well until about 20 days.
Most of populations are sedentary, but hard winters see the northern populations migrating southwards, joining the residents of these southern areas. If weather is too cold, many die. North populations winter south to north Africa, Canary Islands, Near East and south Asia east to north India and central, south east China. A vagrant from ne Siberia wintered for eight consecutive years in central California.