Christoph Kaatz

Long-term satellite tracking sheds light upon variable migration strategies of White Storks (Ciconia ciconia)@@@Langzeit Satelliten-Telemetrie beim Weißstorch gibt Hinweise auf variable Zug- und Überwinterungsstrategien

During investigations on the migration of 120 individual White Storks by means of satellite tracking, four birds were tracked into their winter quarters several times, one bird on nine successive journeys. These storks did not exhibit strong winter-site fidelity, but instead occupied somewhat different winter quarters from one year to the next, probably depending on the food supply. Bisher konnten wir 120 Weißstörche auf ihrem Zug mit Hilfe der Satelliten-Telemetrie verfolgen, 4 Vögel mehrfach und einen auf neun aufeinander folgenden Wanderungen. Dabei zeichnet sich ab, dass Weißstörche im Gegensatz zu vielen anderen Afrikaziehern nur geringe Winterquartiertreue zeigen und im Laufe von Jahren in verschiedenen Gebieten überwintern, wahrscheinlich in Abh ängigkeit vom Nahrungsangebot.

Satelliten-Telemetrie der Jahreswanderungen eines WeißstorchsCiconia ciconia und Diskussion der Orientierungsmechanismen des Heimzugs

In a female White Stork the complete migration cycle could be tracked by satellite from the nesting site to the wintering grounds in the Sudan and Tanzania and back to the nest. The migration route extended over 16 000 km, autumn migration lasted 100 days, homeward migration 70 days, wintering 58 and 41 days in northeastern and southeastern Africa, respectively. The maximum daily route was about 350 km. Up to Turkey the bird migrated together with its male. Homeward migration was performed within a relatively narrow corridor in which autumn migration took place, but in detail the routes of the two migratory seasons showed substantial differences. These data together with those from some raptors in which complete annual migration cycles could be tracked indicate that homeward migration is based on navigation (vector navigation and/or true navigation) rather than on route reversal.

Satelliten-Telemetrie beim WeißstorchCiconia ciconia: Wanderung eines Ost-Storchs in den Süd-Jemen@@@Satellite-tracking of White StorksCiconia cinonia: Migration of an eastern individual to South Yemen

Here we report on an unusual migratory route of a White Stork within the eastern migration corridor (east of the Central European migration divide) to the Arabian peninsula as far as South Yemen. White Storks migrating to and wintering in this area are scarce and their routes there and back — four being under discussion in the literature — are unknown. The 14-year-old breeding female from eastern Germany that we have investigated chose a route passing from Central Europe so far east as to touch the western Ukraine. Around the Gulf of Iskenderun the stork flew in the typical way, performing a migration bend to the right. But when passing Syria the stork again took an extremely easterly route. From the area of Damascus it did not follow the normal southwestern corridor through Jordan to Israel but flew in a southern direction to Saudi Arabia and along the eastern coast of the Red Sea to South Yemen. There, it was unfortunately shot. It remains open whether this migration-experienced adult bird made an orientation “error” in its old age or whether it might already have wintered on the Arabian peninsula in previous years.Here we report on an unusual migratory route of a White Stork within the eastern migration corridor (east of the Central European migration divide) to the Arabian peninsula as far as South Yemen. White Storks migrating to and wintering in this area are scarce and their routes there and back — four being under discussion in the literature — are unknown. The 14-year-old breeding female from eastern Germany that we have investigated chose a route passing from Central Europe so far east as to touch the western Ukraine. Around the Gulf of Iskenderun the stork flew in the typical way, performing a migration bend to the right. But when passing Syria the stork again took an extremely easterly route. From the area of Damascus it did not follow the normal southwestern corridor through Jordan to Israel but flew in a southern direction to Saudi Arabia and along the eastern coast of the Red Sea to South Yemen. There, it was unfortunately shot. It remains open whether this migration-experienced adult bird made an orientation “error” in its old age or whether it might already have wintered on the Arabian peninsula in previous years.

Satelliten-Telemetrie beim WeißstorchCiconia ciconia: Wanderung eines Ost-Storchs westlich bis Nigeria@@@Satellite-tracking of White Storks: Migration of an eastern individual westward as far as Nigeria

A male White Stork, for the first time equipped with a mini-transmitter operated by a solar battery, was tracked on the eastern migration route from E Germany to central African winter quarters and during part of the return migration, for a total distance of about 10 000 km. The individual moved westward into Nigeria, i.e. into the wintering area of western Storks. Since a number of other eastern Storks were tracked as far as Chad, the possibility is discussed that individuals migrating to central Africa along the eastern or western route may eventually return on the opposite route when attracted to flocks of the population from the other side of the migration divide. Some ringing recoveries are consistent with a U-shaped abmigration.