Autumn migration almost over
Newsletter 25/11/2015
As already reported, the autumn migration 2015 started in time mid of August, when the birds left their breeding sites at Burghausen in Bavaria and Kuchl in Salzburg. All birds met near the airport of Salzburg and remained there.
At the end of October we decided to intervene, to avoid that the birds are endangered by an onset of winter. Our main assumption was that the large number of 10 juveniles, compared to 7 adults, caused the extended stopover. Consequently, we separated one adult and two juveniles and translocated them to the entrance of the valley Zillertal north of the Alps. From there, they immediately flew southwards and within 5 days they reached the wintering area.
Subsequently also the remaining group started to move. For example, at the beginning of November, a group of six birds, three adults and three juveniles, migrated on their own to an area near Innsbruck and remained there. About mid of November, we caught them and transferred them just 30 km further south, across the Brenner Pass to Sterzing. From there, all of them continued their journey.
Finally and just in time before the onset of winter with temperatures far below 0°C, all birds crossed the Alps. On Nov. 24th another three birds including one juvenile reached the wintering area. Further eight birds are on the way, some of them are still in the Po-Valley, and others are at the Apennine or already in Tuscany.
The birds are escorted by four members of our team, Anne, Corinna, Daniela and Rachele. The girls follow the birds due to the GPS locations we receive from each single bird several times a day. At stopover sites they care for the birds and they inform hunters, media, police and the public about the birds and the project. This way the birds should be protected from illegal hunting.
It is not yet fully understood why the birds interrupt their autumn migration journey on the north edge of the Alps since 2014. It seems to be a combination of different factors, including social dynamics and extraordinary mild temperatures during autumn and early winter, causing the birds to delay the crossing of the mountain range. We are in discussion with scientist to gain further insight into this problematic but also interesting phenomenon.
Foto: Dott. Corrado Zanini
Click here to get to our Newsletter archive.