2002 Movements of Yellow-legged Gulls 101 MOVEMENTS OF YELLOW-LEGGED GULLS LARUS [CACHINNANS] MICHAHELLIS1 FROM TWO SMALL WESTERN MEDITERRANEAN COLONIES

legged Gulls Larus [cachinnans] michahellis from two small western Mediterranean colonies. Atlantic Seabirds 4(3): 101-108. In this study we analyse recoveries and resightings of ringed Yellow-legged Gulls Larus [cachinnans] michahellis from two small colonies located along the E and SE Mediterranean Iberian coast. Results show that birds follow the same migratory routes as birds of other colonies of the western Mediterranean. Gulls move to the Atlantic coast of France and Iberia after fledging, where they summer and winter, although equally important numbers probably remain close to their natal colonies. Immature gulls (1y + 2y) seem to return and stay in the vicinity of their natal colonies during spring. Long-range movements target Atlantic areas with a high primary production during periods of food scarcity in the western Mediterranean. Adult gulls probably do shorter-term long-range dispersal movements than juveniles and immatures, owing to their larger experience on where to find alternative food sources