[Authority] Boddaert, 1783 | [group] Old World warblers | [order] PASSERIFORMES | [family] Sylviidae | [latin] Sylvia undata | [UK] Dartford Warbler | [FR] Fauvette pitchou | [DE] Provence-Grasmucke | [ES] Curruca rabilarga | [NL] Provencaalse Grasmus | copyright picture

copyright: J. Rochefort

Small warbler, with spiky bill, rather high crown, short wings, and strikingly long tail. Attitude rather like Wren on perch, but looks long and slim in flight. Essentially dark slaty-brown above, brown-pink below in male, somewhat paler in female and juvenile. White tail-edges are not prominent. Eye and eye-ring of adult dirty orange to red, and bill base yellowish.

Shows some preference for maritime regions and islands, but in south of range ascends to uplands, and even to c. 1500 m in Spain. In southern Europe, mainly frequents open garigue- in north-west Spain, also in low pine woods- in North Africa, confined to largely hilly coastal scrub with kermes oak. In England, breeding habitat is almost entirely lowland heath dominated either by gorse or by heaths- in some places, bramble and, to less extent, bracken or grasses may serve as substitutes.

Sylvia undata is a patchily distributed resident across parts of south-western Europe, which constitutes >95% of its global range. Its European breeding population is very large (>1,900,000 pairs), but underwent a large decline between 1970-1990. Although the trend of the stronghold population in Spain during 1990-2000 was unknown, the species was stable or increased elsewhere in its European range. Nevertheless, its total population size has probably not recovered to the level that preceded its decline, and consequently the species is provisionally evaluated as Depleted.
This small warbler inhabits north-western Africa and south-western Europe, from the Iberian Peninsula to Italy and southernmost England. Parts of its populations are sedentary- parts make small-scale movements and a few birds reach north-western Africa. The population of the European Union, which represents nearly the entire world population, is estimated at 1.8-4.1 millions of breeding pairs. However, since the beginning of the 1970s, this species is declining in Spain. Elsewhere it fluctuates or remains stable. Intensification of agriculture and habitat destruction - Mediterranean thickets in the south, dry heath in the north - are the main threats to this species. Too frequent fires are also detrimental

Diet includes the following: Invertebrates: damsel flies, grasshoppers, bugs, adult and larval moths and butterflies, flies, wasps, beetles, spiders, harvestmen, millipedes and snails. Plant material: berries of bramble Rubus, spurge-laurel Daphne, myrtle Myrtus, pistachio Pistacia.
Observed carrying caterpillars from heather to gorse where they were beaten on stem. In summer, seen to pick and presumably eat small items while carrying caterpillar for young. Adults feed moths to young complete with wings. Large grasshoppers are fed whole, abdomen first.

This species is declining at a moderately rapid rate, qualifying the species for uplisting to Near Threatened. Declines in the core population in Spain were largely responsible for the global declines- the drivers are not entirely clear but include habitat degradation and modification. [conservation status from birdlife.org]

Egg laying in Southern England from mid-April. Jersey (Channel Islands) eggs at end of March to July. Provence (southern France) and southern Spain: eggs from early April. usually 2 broods, exceptionally 3. Nest is built in dense, often evergreen bushes. Nest is a compact cup of grass leaves and stems, and bits of heather, usually with vegetable down, cobwebs, and occasionally feathers, sometimes with distinct middle layer of plant down- lining (inner layer) of finer material including rootlets and hair. Clutch varies from 3-5 and are incubated for 12-14 days.

Partially migratory and dispersive. Many birds remain all year on breeding grounds, but autumn and winter records are frequent in non-breeding areas, probably chiefly juveniles. In Mediterranean, presence in winter on islands where none breed shows that some birds undertake sea crossings: scarce but regular visitor to Malta and Balearic Islands (and Menorca now colonized: see Distribution). Some European birds reach north-west Africa, vagrants occur far afield.