Our previous telemetry tracking of the Yelkouan shearwater showed the importance of the Black Sea as a major area visited by the Yelkouan Shearwater, an endemic seabird known to breed only in the Mediterranean. Furthermore, there is indication that Yelkouan Shearwaters from Eastern Mediterranean colonies utilize the Black Sea even during the reproductive season, repeatedly passing through the Bosphorus on extended foraging trips. Like a bottleneck connecting the Mediterranean Sea to the Black Sea, the Bosphorus Strait represents an ideal location to catch Yelkouans at sea and tag them with GPS live transmitters to track their ‘return’ routes towards their nesting sites.
This mission was organized in collaboration with the Inst. of Env. Sciences – Istanbul University, the Turkish Marine Research Foundation (TUDAV), Bogazici University, and the Department of Biology – Ege University.
To capture birds at sea, the team employed a technique first utilized 28 years ago in the Istanbul Strait by, with the assistance of its original designer (Asaf Ertan), involving the deployment of a long net towed between two vessels. Thirty yelkouan shearwater birds in the İstanbul Strait were fitted with GPS/GSM transmitters and ID bands. The transmitters attached to the birds’ back feathers transmitted location data for approximately two/three months until they naturally fell off, providing precious information about the migration routes and breeding colonies of this unique and threatened species.
Method used to capture Yelkouan shearwaters in 1996 and adaptation of the method in February 2024.
Close-up of a GPS/GSM transmitter attached to the back feathers and the individual ready to be released.
Click here to discover all the tracks.