helen raine

Satellite tags were attached to ten juvenile Yelkouan Shearwaters from a breeding colony in Malta to study post-fledging dispersal patterns. Of the eight birds with usable data, all moved eastwards almost immediately after leaving their nest sites. The majority of birds migrated to the islands off the western coast of Greece with one then moving on into the Aegean Sea and another to the South Adriatic Basin. While most birds migrated to Greek waters, two followed a different route, undertaking a wide circuit of the eastern Mediterranean and eventually ending up along the northern coast of Africa. The bird that transmitted for the longest period (68 days) was last recorded in the northern Aegean where it had spent the majority of the time. This study has shown that Maltese Yelkouan Shearwaters range over a large area during the first few weeks of fledging and follow widely varying routes. It has also demonstrated the importance of Greek waters for juvenile Yelkouans from Maltese colonies. The difficulty in tracking juvenile Yelkouan Shearwaters using this method has been highlighted by this study, and it is suggested that further methods are explored to track juvenile birds during the months after fledging.

Three juvenile Cory's Shearwaters Calonectris diomedea diomedea were fitted with back-mounted satellite tags and tracked during post-fledging migration. The birds spent several weeks in the central Mediterranean before migrating westwards. Two tags stopped transmitting after 21 and 35 days; the third bird passed through the Strait of Gibraltar and along the West African coast until transmitting ceased after day 43, by which time it was 114.6 km off the coast and 4,390 km from Malta. Cory's Shearwaters from other Mediterranean islands winter further south in equatorial waters, in the eastern South Atlantic or in the northeast tropical Atlantic associated with the Canary current, and further research is needed to define the wintering areas of Maltese Cory's Shearwaters.