Marmora's Warbler Curruca sarda Scientific name definitions

12·5 cm; 8·5–12 g. Rather small, fairly long-tailed warbler with short, rounded wings; bulkier and less graceful than <em>C. balearica</em> . Male  breeding has bluish slate-grey head  and blackish frontal mask  ; upper­parts and upperwing-coverts slate-grey, slightly less bluish than head  ; remiges blackish with greyish fringes; alula black with whitish fringes, thinner on largest feather; tail blackish, outermost feather with grey fringes and whitish tip and edges, next two pairs similar but with pale areas smaller; chin and throat dusky grey, when very worn largely concolor­ous with upperparts; underparts  mostly grey, darker on breast and flanks, paler and more whitish-cream on mid-belly; iris reddish-orange and orbital ring reddish  (contrasting with darker head), eyering mostly of grey and white feathers; bill pale flesh-pink, blackish culmen and tip; legs mostly pale orange-brown to brownish. Male in non-breeding plumage is tinged brownish on upperparts and wing-coverts, with blackish facial mask less distinct, has greyish-white throat and mostly whitish chin; underparts warmer-coloured than in spring, especially on flanks and belly. Female breeding resembles non-breeding male, but upperparts more markedly suffused brown (mostly on mantle and scapulars), remiges and wing-coverts fringed less pure grey and with rustier tone, particularly on inner feathers, underparts overall buffier with more extensive whitish on throat and belly; non-breeding female similar, but with more brownish tinge above and whitish below, especially on throat and centre of belly. Juvenile has slaty earth-brown upperparts with slight buffish tinge, pale tips and edges of outermost rectrices sandy-buff, largely pale grey-brown below, darker on chest and flanks and tinged whitish-buff, especially on rear-flanks and belly, iris olive-brown, orbital ring dull reddish-brown, legs greyish-brown; first-winter like respective adult, but with juvenile-like bare parts and unmoulted flight-feathers.

Formerly included C. balearica as a race; see that species. Monotypic.

Corsica and Sardinia and some off-lying islets, also on a few islands off W Italian coast (Capraia, Elba, Pianosa, Montecristo) and Pantelleria; non-breeding also N Africa (N Algeria E to NW Libya).

Favours uniform, low Mediterranean scrubland (c. 0·5–1 m tall), such as Cistus garrigue  and low to medium-height maquis of tree-heath (Erica arborea), strawberry-tree (Arbutus unedo) and Pistacia lentiscus; occupies also more sparse scrubby grassland and degraded garrigue, as well as the very first stages of wildfire succession. Avoids forested areas. During non-breeding season and on N African wintering grounds, found also in more grassy areas and steppes with dense vegetation. During breeding occurs from sea-level to c. 1800–2000 m.

Most of population resident. Some altitudinal movements, linked to snow cover. Some, mostly first-winters, undertake dispersal to short-distance movements to Sicily and N Africa (S to c. 32º N), mostly between Nov and Mar. Regular passage in very low numbers through Balearic Is and islands in Tyrrhenian Sea in spring (apparently mainly mid-Mar to mid-Apr); overshooting migrants sometimes reach Mediterranean coast of SW Europe; rarely, spring vagrants establish territories for several days on NE coast of Spain, and even in England.

Diet mainly spiders (Araneae) and small insects and their larvae. Nestlings fed with lepidopteran caterpillars and pupae, flies (Diptera), grasshoppers (Orthoptera) and large numbers of spiders. Forages mostly in low strata of scrub and bushes, c. 0–1 m above ground; often flycatches in manner reminiscent of Spotted Flycatcher (Muscicapa striata).

Song , from perch, less frequently from within cover or in song flight, composed of short twittering warbles (1·5–4·2 seconds long) initiated by higher-pitched, questioning notes and followed by rather clean and repetitive rolling trill; distinctly sweeter and less raucous than that of C. balearica. Common contact call a guttural short “tsek”, louder and harder-ended than homologous call of C. balearica and distinctly monosyllabic.

Season mostly Mar–Jul, with main laying period between early Apr and late May; one or two broods. Monogamous; solitary, territorial breeder. Song flight a steady, fluttering ascent to c. 4–7 m above ground, ending with rapid plunge into cover. Male builds unlined “cock nests”; breeding nest constructed by both sexes, work lasting up to several weeks early in season and only a few days later on, a solidly structured deep cup with broadened rim, made from grasses, stems and leaves, lined with finer grass, hair and roots, placed 60–140 cm (mean 95 cm) above ground in low bush or dense scrub, rarely directly on ground in recently burnt areas. Clutch 3–5 eggs (mean 3·8), usually 3 in Apr and 4 in May, laid at 1-day intervals (rarely, two laid in less than 24 hours); incubation by both sexes, period 12–15 days; both also feed chicks, nestling period c. 12–13 days; young tended by adults for up to 4–5 weeks after fledging. In study of 20 nests in Corsica, success 60% (hatching success 71%, fledging 85%), 59% of fledged young reached independence.

Not globally threatened. Common to very common in favourable habitats. By 2000, total population estimated at 15,000–50,000 breeding pairs (10,000–40,000 in Corsica and 5000–10,000 in Sardinia); considered stable. Densities range from 3–4·5 pairs/10 ha in Corsica to 2–7·7 pairs/10 ha in Sardinia. Occasionally breeds in mainland Italy (Argentario Peninsula, in S Tuscany); historical records of alleged breeding in coastal E Spain, however, erroneous and probably due to confusion with C. undata. Reports of breeding on Pantellaria (between Sicily and Tunisia) considered dubious; similarly, scarce nesting records from Greece (Náxos, in Cyclades, also Crete) poorly documented and of doubtful validity. Forest fires can benefit this species, since it is capable of colonizing burnt areas one year after fire.