Spotless Starling Sturnus unicolor Scientific name definitions

22 cm; 70–100 g. Medium-sized starling with feathers of crown, nape, throat and upper breast greatly elongated (up to twice length of same feathers on S. vulgaris). Male has black body plumage with metallic iridescence, purplish on head and upper breast, oily green on back and belly; wing blackish, some mauve gloss on outer webs of innermost remiges; tail blackish-brown; iris dark brown; bill yellow with blue to bluish-black base; legs pink or reddish-pink. In fresh plumage (after post-nuptial moult), feathers have greyish margins, producing slight grey bloom; occasionally, elongated feathers of head and upper breast have small V shaped white markings at tip, but such markings more commonly restricted to belly; male becomes more glossy as feathers abrade and all tips and margins lost; bill black in non-breeding season; legs duller and usually darker during moult period. Female is similar to male but less glossy, with shorter feathers on head and upper breast, diagnostic paler margins on wing feathers; in freshly moulted plumage, grey margins of feathers produce usually more extensive greyish bloom than in male; more often with small V shaped white markings at feather tips, especially on vent and undertail-coverts, but tips and margins soon abrade (giving unspotted appearance); iris brown, paler inner or outer ring; bill in breeding season yellow with pinkish-brown base; legs brownish-pink. Juvenile is uniformly brown , often darker than juvenile of S. vulgaris, with no streaking on breast or belly, whitish chin and throat, sometimes pale margins on remiges; iris brown, bill blackish, legs brown. After post-juvenile moult, similar to non-breeding adult but with small pale feather tips all over, these still visible in spring at least on undertail-coverts, and often more developed in females; many birds, especially females, have background colour dark ash-grey rather than black.

Iberian Peninsula, S France, N Africa (Morocco, NE Algeria and Tunisia), and Mediterranean islands of Corsica, Sardinia and Sicily.

Omnivorous, animal food  predominating in spring and summer, fruit and seeds in autumn and winter. Vertebrates taken include small frogs and toads (Amphibia), lizards (Reptilia), and shrews (Soricidae) and mice (Muridae); invertebrates  primarily insects, mostly adult and larval  beetles (Coleoptera), especially dung beetles (Scarabaeidae), weevils (Curculionidae), leaf beetles (Chrysomelidae), ground beetles (Carabidae) and grain beetles (Tenebrionidae), but including also grasshoppers (Orthoptera), ants and wasps (Hymenoptera), bugs (Hemiptera), adult flies and maggots (Diptera), caterpillars of butterflies and moths (Lepidoptera), cockroaches (Blattodea) and dragonflies (Odonata); other invertebrates taken are e.g. small snails (Gastropoda), earthworms (Lumbricidae), spiders (Araneae), mites (Acarina), ticks (Ixodida), harvestmen (Opiliones), scorpions (Scorpiones), pseudoscorpions (Pseudoscorpiones), centipedes (Chilopoda) and millipedes (Diplopoda). Plant food consumed includes seeds of docks and knotweeds (Polygonaceae), fruits of nightshade (Solanum), mastic (Pistacea), brambles (Rubus) and oaks (Quercus), and buds and flowers of elm (Ulmus) and poplar (Populus), and nectar of introduced species (Agave, <em>Erythrina</em> ). Diet includes cultivated plants such as cherries and plums (Prunus), grapes (Vitis) and olives (Olea). Over the whole year in Spain, diet 60% animal food and 40% plant food. Most food collected on ground , with open-bill probing used extensively in extracting invertebrates from soil and grass; when foraging with cattle, hawks insects disturbed by the animals, removes ticks and flies from their bodies, and takes insects and seeds from dung. Feed in foliage on defoliating caterpillars during breeding season, and hawks insects; young fed predominantly with animal food. Winter flocks move in "roller-feeding" style, individuals from the rear constantly flying forward to land in front; these flocks often associated with S. vulgaris; in study in WC Spain, present species consistently formed larger feeding flocks than those of S. vulgaris.

Male sings in most months; both sexes sing in winter, and at roost. Song consists of whistles and warbling phrases , which include mimicry of at least 15 other species; similar in structure to that of S. vulgaris, but louder (particularly the whistles). Whistles are most frequent calls in non-breeding season; harsh alarm calls, also high-pitched distress calls recorded. In areas of sympatry with S. vulgaris in NE Spain, both species share same dialect, and interspecific song-matching is frequent, with similarity of repertoire comparable to intraspecific variation of the two in areas of allopatry.

Season Apr to mid-Jul in Spain and Mar–Jul in Morocco; often double-brooded. Primarily monogamous; some males polygynous, and at some colonies majority of males sometimes mated with two females (experimental manipulation of male hormone levels, and provision of additional nestboxes, increased frequency of polygyny); extra-pair copulations occur, primarily by early-breeding males during incubation period of mates. Colonial nester; colonies densest where sufficient nest-sites available, e.g. in roofs. In areas of sympatry with S. vulgaris in NE Spain, mixed colonies frequent, and breeding of both species is synchronized. Nest built by both sexes, mainly from dry grass, lined with grass, roots, leaves and feathers, often yellow flowers included in structure, and fresh green leaves, including those of exotic eucalypts (Eucalyptus), may be added; male adds green leaves prior to incubation, apparently as part of courtship and to stimulate female to lay, female brings feathers during laying and incubation; sited in natural hole or old hole of woodpecker (Picidae) in tree, or in disused burrow of European Bee-eater (Merops apiaster) or Collared Sand Martin (Riparia riparia), or in old nest of White Stork (Ciconia ciconia), Eurasian Jackdaw (Corvus monedula) or sparrow (Passer); also artificial structures widely used, most often sites under roof tiles, or cavity in wall, building or wheat stack; nestboxes used. Clutch 4–5 eggs in Spain, usually 3–4 in N Africa, eggs plain pale blue; incubation mainly by female, period 11 days; chicks fed by both parents, both also remove faecal sacs, female doing larger share of work, nestling period 21–22 days; young  fed by adults for a few days after leaving nest, within a week of fledging form flocks of juveniles, which move away from nesting area. Intraspecific brood parasitism occurs, particularly in first clutches, e.g. at two colonies over four seasons 19–27% of clutches contained parasitic eggs (parasitism up to 40% for first clutches); both male and female eject alien eggs from nest until own clutch started (success of parasitic eggs less than 10%). Of 150 eggs in Spain, 70% hatched and 51% produced fledglings; breeding success in polygynous matings suggests that female quality more important than male assistance in rearing young.