Dispersal of yellow-legged gulls larus michahellis ringed in algeria: A preliminary analysis

Abstract

Ringing of yellow-legged gulls Lams michahellis michahellis begun in Algeria in 2009, the first scheme of its kind in North Africa. Ringing of chicks was initiated at Skikda and extended a year later to four other colonies located along the Algerian coast. Preliminary analysis of observations of ringed yellow-legged gulls from Algerian colonies indicates that juveniles dispersed in a northwesterly direction to the Balearic Sea and the Bay of Biscay, and westwards to the Alborán Sea and the Iberian Atlantic coast from Cádiz Bay to Galicia. Preliminary results suggested two distinct routes: gulls from the eastern Algerian colonies moved N/NW to eastern Spain and overland to the Bay of Biscay, a pattern of dispersal previously reported for birds from Spanish and French western Mediterranean colonies. Juveniles from western colonies seemed to move N/NW to the Alborán Sea and Cádiz Bay. In Spain, to where most dispersal occurred, the data suggests that Algerian gulls summered at coastal areas before returning to North Africa in late autumn and winter.