Bird lovers can follow geese on their way to the breeding grounds
Verden / IWWR
Spring is advancing, and this also applies to northern Europe. As soon as the snow has melted there, the Barnacle Geese set off for their breeding grounds. They are leaving the salt marshes of the Wadden Sea, where they have recently built up the energy reserves needed for the 2,500 to 3,500 km migration. In a research project by the Institute for Wetlands and Waterbird Research (IWWR/Verden) and the Research and Technology Centre of Kiel University (FTZ Büsum), ten Barnacle Geese were fitted with GPS transmitters in April and released. Their data can be viewed online every day, so that all nature lovers have the opportunity to follow this journey to the Arctic north.
The researchers have set up a website for following the goose migration:
The data are automatically displayed on a map. The transmitters can also be followed with the "Animal Tracker" app from the Max Planck Institute of Animal Behavior. It is available free of charge in the iOS and Android app stores and also shows many other bird species.
Modern electronics now make it possible to use transmitters even on medium-sized birds such as Arctic geese weighing less than 2 kilograms, collecting almost unbelievable amounts of data. "These transmitters currently record a GPS fix every 5 minutes, plus data on the geese's behaviour," says Dr. Helmut Kruckenberg, migration researcher at IWWR e.V. "In flight, this data rate increases to every 30 seconds. The transmitter detects this automatically." The researchers want to find out more about the flight movements of the geese in the North Sea region. According to Kruckenberg, the data also provide information on the detailed use of the individual types of salt marsh. The transmitters record the bird's position to within a metre, so that the data can later be processed with satellite images of the Wadden Sea and detailed terrain maps. The researchers are also interested in the geese's migration routes, especially the way in which the geese cross the Baltic Sea. "Many offshore wind farms have already been built here, and more are planned," explains Helmut Kruckenberg. The biologists from Kiel and Verden have been studying the impact of these on the birds' migration routes for several years.
By the first weekend in May, almost all the birds had left. One tagged bird is still staying in the Leybucht. "Of course, the geese don't all migrate at the same time," reports the biologist. "When the wind is favourable and their individual energy reserves are sufficient, the birds take off." The bird expert estimates that the departure of the geese will continue until mid-May. This also depends on whether the birds breed at all in the coming season. If they do not want to or cannot, for example because they are not yet sexually mature or have lost their partner, they have considerably more time, says Kruckenberg.
In total, almost 100 geese were caught in two catching campaigns and marked with coded colour rings on their legs. This international marking of Barnacle Geese has been used since 1976. A large online database allows every observer to report readings of these birds as part of a citizen science project. The bird's life history can be viewed immediately at submit.cr-birding.org.
Most of the geese crossed the Baltic Sea within a few hours and are currently resting in Estonia or Finland. As soon as they cross the Russian border, the experts expect fewer data. "Because of the war, Russia has restricted mobile internet and is also actively jamming GPS signals," says Kruckenberg. So it will be exciting to see how often the birds report in on their way to the nest.
Institute for Wetlands and Waterbird Research e.V.
http://www.gänseforschung.de