The Brent geese that migrate to the Wadden sea this year will have very few young birds with them. This prediction is based on the research conducted by Bart Ebbinge and Bart Nolet and their expedition to the Taimyr peninsula in Siberia. During this expedition, Alterra, part of Wageningen UR, and the Netherlands Institute of Ecology studied the relationships between polar animals and the role of climate in these relationships.
Last summer turned out to be disastrous for the nesting geese. The birds had many problems with roving snowy owls, pomarine skuas, sea gulls and polar foxes. During a normal year, these animals primarily eat lemmings. However, the lemming population on the Taimyr peninsula collapsed early in the season. The carnivores then turned to the nests of the Brent geese. The winter in Siberia was a long one this year. When the snow and ice finally began to melt, the few remaining goose eggs were carried away on the water. According to Bart Ebbinge, the situation was exceptional. Normally, much of the snow and ice is gone by the time the Brent geese start to nest.
The development of the lemming population was unusual this year as well. The rodent has a natural three-year cycle. This year, many lemmings were expected, because the last lemming peak year of 2005 was exactly 3 years ago However, for unexplained reasons, the lemming population had already collapsed during the winter. Was this caused by insufficient food? A short thaw during the past winter? Or something entirely different? Bart Ebbinge: “We simply don't know. To the west of the Urals, in the European part of the Russian tundra, the month of July was much warmer. As a result, the snow disappeared very quickly, and with some delay many Egyptian geese were able to breed there. In this part of the Russian tundra there are very few lemmings in other years, so that the breeding success of the geese is not so strongly affected by the lemming cycle."
The expedition took place as part of the International Polar Year (IPY). An extensive weblog on this expedition can be found on the website of the VPRO. Since the beginning of this year, the Natuurkalender has been tracking a number of Egyptian geese on their migration between their overwintering area in the Netherlands and their breeding area in North Russia. At every position, the local temperature can also be seen. In this way, you can follow the route of the geese (with radio tracking devices), which have been given names such as Kees, Marco, Melis, Eric, Cas and Kramer, and see how cold it is when they leave the Russian tundra to migrate to the Netherlands