Exciting start of the autumn migration
Newsletter 19/10/2020
With 27 fledglings in 9 nests the breeding season in Burghausen and Kuchl is successfully concluded. Similar to the last years, the birds left the two breeding areas in August and merged in Salzburg. Six birds from the sedentary colony at the Konrad-Lorenz Research Centre in Grünau im Almtal also joined this group, which currently consists of a total of 53 birds.
In recent years, we have learned that the direct flight route from Salzburg to the south seems to be an unfavourable migration pathway for the Northern Bald Ibis. The birds fly into the upper Salzach Valley and from there either follow a direct southern course to Carinthia or continue their migration over the Gerlos Pass into the valley Zillertal and further to South Tyrol. On this migration corridor we frequently observe approaches, which are aborted unsuccessfully. This causes delay and the animals face the risk of getting stuck due to the onset of winter. We assume that the birds continue to choose this corridor because we have guided the founder individuals along this route in the course of human-led migrations.
At the same time for the last years, more and more birds began to fly along a second more western migration corridor, both in autumn and in spring. This corridor leads into the Inn Valley and then either over the Zillertal and the Pfitscher Joch or the Brenner Pass to South Tyrol. This western route seems to be much more efficient for the birds, we hardly observed any unsuccessful approaches there.
We have therefore decided to promote this western corridor, by transferring birds from Salzburg to the Lower Inn Valley. We have already done this with smaller groups in previous years and have made good experience with this approach. This year we did it on a larger scale. In the last ten days four members of our team have transferred a total of 31 birds. 2 subadult Ibises were already located in the Inn Valley, thus currently 33 birds are in the Inn Valley, while another 20 birds are still in the province of Salzburg.
For the first time, two juveniles from the sedentary colony at the Konrad-Lorenz Research station joined our group. We expect them to join our birds to migrate to Tuscany. They carry GPS devices, so their flight paths can be tracked.
The decision not to wait any longer this year, but to carry out the transfer on a larger scale already at the beginning of October, is also connected to the increasing restrictions due to the COVID pandemic. We must expect to be severely limited in our field management later in the year. Unfortunately, this assumption is already confirmed. For example, a quarantine was imposed on the community of Kuchl in the province of Salzburg, where one of our breeding areas is located.
The autumn migration in the breeding colony Überlingen at Lake Constance has also begun in an exciting and very positive way. All 12 birds, which spent the summer in this region, are on their way south. Two birds have already reached the winter area.
Since last year, another migrating breeding colony has been established in Carinthia with juveniles from the sedentary colony at Zoo Rosegg. While the sedentary Rosegg birds were recently brought into the aviary to spend their winter, 37 juveniles remained in free flight. To establish a new migratory tradition in this colony we merged those juveniles with 6 migration experienced leader birds from our colony While 12 individuals are currently still in Carinthia, 31 of the 45 Northern Bald Ibises are already in Friuli south of the Alps.
Picture:
A total of 108 Northern Bald Ibises are involved in this year's autumn migration, the highest number since project start. Most of those birds are tagged. You can follow their autumn migration using the App Animal Tracker; picture Rudolph Beck.
