| Habitat and Ecology: |
Behaviour Most populations of this species are fully migratory and travel along coastlines between their breeding and wintering areas (del Hoyo et al. 1996, Olsen and Larsson 2003) (although a minority travel inland across Asian Turkey or follow major river valleys through Eastern and central Europe) (Snow and Perrins 1998). The species returns to its breeding colonies from late-February (Olsen and Larsson 2003) to early-April, with most beginning to breed from early-May (del Hoyo et al. 1996). The Autumn migration to the wintering grounds occurs from late-June onwards (Olsen and Larsson 2003). The species breeds in colonies, usually of less than 1,000 pairs and occasionally in single pairs amidst colonies of other species (del Hoyo et al. 1996). It often breeds near but not among Sandwich Terns Thalasseus sandvicensis, or intermingling with Larus ridibundus (del Hoyo et al. 1996). When breeding in coastal areas the species may fly up to 80 km away from the colony to feed on inland grassland (del Hoyo et al. 1996). Habitat Breeding The species breeds on the Mediterranean coast at lagoons (del Hoyo et al. 1996), estuaries (del Hoyo et al. 1996, Snow and Perrins 1998) and sometimes coastal saltmarsh (del Hoyo et al. 1996), often also breeding inland on large steppe lakes and marshes in open lowland areas (del Hoyo et al. 1996, Snow and Perrins 1998). It nests near water on flood-lands, fields and grasslands (del Hoyo et al. 1996, Snow and Perrins 1998) and on wet or dry areas of islands (Snow and Perrins 1998), favouring sparse vegetation but generally avoiding barren sand (del Hoyo et al. 1996). Non-breeding Outside of the breeding season the species becomes entirely coastal (del Hoyo et al. 1996), favouring estuaries (Urban et al. 1986, del Hoyo et al. 1996), harbours (del Hoyo et al. 1996), saline lagoons and other sheltered waters (Urban et al. 1986). Diet Breeding During the breeding season its diet consists of terrestrial and aquatic insects, gastropods, small numbers of fish and rodents (del Hoyo et al. 1996). Non-breeding When not breeding the species takes marine fish, molluscs (Urban et al. 1986, del Hoyo et al. 1996), insects (Urban et al. 1986) (e.g. beetles and grasshoppers) (Milchev et al. 2004), earthworms, berries (Urban et al. 1986), seeds (e.g. of barley, wheat, sunflowers and ragwort) (Milchev et al. 2004), offal (del Hoyo et al. 1996) and occasionally sewage and refuse (del Hoyo et al. 1996). Breeding site The nest is a shallow depression, situated on the ground in sparsely vegetated sites, thickets or reedbeds (del Hoyo et al. 1996) near water (Snow and Perrins 1998). The species breeds in dense colonies, with neighbouring pairs c.60 cm apart (del Hoyo et al. 1996). Management information Artificially constructed nesting sites in coastal locations such as beaches of bare shingle and islands or rafts covered with sparse vegetation are successful in attracting breeding pairs of this species (Burgess and Hirons 1992). A conservation scheme for the protection of gull and tern breeding colonies in coastal lagoons and deltas (e.g. Po Delta, Italy) involves protection from human disturbance, prevention of erosion of islet complexes, habitat maintenance and the creation of new islets for nest sites (Fasola and Canova 1996). The scheme particularly specifies that bare islets with 30-100 % cover of low vegetation (sward heights less than 20 cm) should be maintained or created as nesting sites (Fasola and Canova 1996).
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