On the move
Newsletter 26/11/2019
Start-up of a new breeding colony
This year, for the first time, 18 young Northern Bald Ibises which grew up in Tierpark Rosegg in Carinthia were equipped with GPS devices and left outside the aviary; the remaining individuals of this sedentary zoo colony were, as usual, transferred to the aviary at the end of September. Five of our adult experienced migratory birds were transferred to the free-flying juveniles, hoping that they’ll guide the young ones to the common wintering area in southern Tuscany.
We observed the behaviour of this Carinthian group with interest. On the one hand, we are implementing a new methodological approach with these birds; on the other hand, their behaviour during the autumn migration is an important reference to that of the Northern Bald Ibises staying north of the Alps. We expected a cross-regional synchronicity in the movement patterns of these groups, as has been repeatedly observed before. In both groups, we observed no such patterns until November. A few days ago, however, the Northern Bald Ibises started to move further south, and on November 22, a larger group of birds tried to cross the Alps for the first time. Adverse weather conditions, however, forced them to turn back again.
We waited apprehensively for the positioning data of the Carinthian birds. In the afternoon, finally, the majority of these birds departed from the municipality of Ferlach. They crossed the Karawanken at Loiblpass and flew to the Lido di Jesolo (180 km). The next day the group split up. Three young birds and two adults flew on to the Apennine near Arezzo (305 km) and reached the wintering area the next day (170 km). Thus, we successfully implemented two new methodological approaches this year: In June, we transferred two breeding pairs with their nests and chicks from an artificial rock niche to the rock face at Georgenberg in Kuchl, Salzburg (“nest transfer”), and now we were able to unite young, inexperienced birds with adult ones to migrate to the common wintering area (“union”).
These successfully applied methods are essential for the continuation of our project. However, they also generally expand the possibilities for species conservation in colony breeders and migratory birds. A variation of the "union" method was already applied in 2010 under the direction of members of our team near Palmyra in Syria. Three remaining wild birds were to lead three young birds from a Turkish breeding colony to the wintering area in Ethiopia. The young birds actually followed an adult individual to the Yemeni border. There the group split up. Ideally, one could have built on this partial success. However, the project ultimately failed due to the extremely difficult political, social and environmental conditions in the countries concerned. The Syrian Northern Bald Ibis population has been extinct since 2013.
The synchronicity between the independent groups north and south of the Alps proves that this year's delays in the autumn migration are not a random erratic behaviour of the birds, but the result of variable external circumstances. This is probably one of the most important findings in our project. If we relate the timing of the birds to the transregional weather conditions and their consequences, then we will better understand the migratory behaviour of the Northern Bald Ibis and may, if necessary, adjust the management as the reintroduction progresses. The fact that this synchronicity can be observed particularly well under the conditions of our project also makes the Northern Bald Ibis an indicator species in the context of climate change. We hope that the current good weather conditions allow the remaining birds north and south of the Alps to continue their migration journey towards south.
Picture (AG Schmalstieg): Robigus, one of the young birds after its arrival in the wintering area.
Click here to get to our Newsletter archive.
