Ongoing Autumn Migration
Newsletter 30/10/2015
Yesterday, October 29, a group of three migrating Northern Bald Ibises reached our wintering area WWF Oasi Laguna di Orbetello in southern Tuscany. The group consisted of one experienced adult male migrant, called JAZU, and two juvenile birds.
The journey lasted for 6 days, five flight days with a mean of 120 km/day and one stopover at a rainy day. During the journey, the birds had to cross the Alps and the Apennine, with a maximum flight level of about 2.200 m msl.
All birds were equipped with GPS trackers. Daniela Trobe from our team accompanied the birds by car following the GPS positions. Escorting the birds is mainly necessary to protect them from illegal hunting, which is the major threat for the migrating birds.
JAZU belongs to the first generation of Northern Bald Ibises that learned this migration route not from humans but from adult conspecifics. Now, JAZU passed this information to the birds from the next generation. This way the new migration tradition becomes established.
In the wintering area the three birds met up with a large group of 61 Northern Bald Ibises. This group mainly consist of subadult birds, which remain in the wintering area until sexually mature, and of handraised juveniles, which followed a microlight aircraft some weeks ago from Austria to Tuscany.
These three birds were originally part of a larger migratory group consisting of 7 adults and 10 juveniles, all from the breeding areas Burghausen in Bavaria and Kuchl in Salzburg. For weeks, the birds remained south of the city of Salzburg. It seemed that the large and homogenous group of inexperienced juveniles prevented the whole group to depart towards the wintering area.
Finally, we decided to split the group and to transfer JAZU with two juveniles to the entrance of the valley Zillertal/Tyrol. Indeed, the next day they started their exciting migration journey. The rest of the group is still in Austria, but most of them departed from Salzburg. So during the next days we expect further birds to cross the border to Italy.
A reasonable and sound management of the birds is a necessary part of the reintroduction program. This also includes translocation of birds. The migration tradition is expected to become more stable and standardized with an increasing number of experienced migrants in the group.
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