Migratory birds sensitive to climate change
The International Wadden Sea area, with its 14.7 thousand km ², is the most significant resting, moulting and wintering ground for waterfowl and waders East-Atlantic flyway between the Arctic and South Africa. In 2009 the high national and international protection status of the territory was recognized by inscription of the Wadden Sea into the UNESCO World Heritage list.
The International Wadden Sea Secretariat has now released a common report on the status of shore birds, which additionally examines trends of the arrival and fly-away periods of the birds, the distribution of bird species in the various regions and the potential impact of climate change over the last 21 years.
14 bird species out of 34 of all counted, such as oystercatchers, avocets, Kentish plovers, herring gulls and others, have reduced in quantity significantly, while 20 species such as Eurasian spoonbill, bar-tailed godwit, sanderling and grey plover show an increase. Particularly species that breed and hibernate in North, Central or Western Europe seem to be influenced by the conditions in North-West Europe, which has a negative impact on the trends.
Some bird species, especially those that breed in the Arctic or in northern Europe, come in spring to the Wadden Sea later as 20 years ago, which can possibly be attributed to climate change. In last decades the distribution of birds in the Wadden Sea region seems to depend on the environmental changes. For many species, that also seek food in mudflats, in the last 21 years the trend in Denmark and the Netherlands has remained stable, while the numbers in Schleswig-Holstein and Lower Saxony show a negative trend. In this example the correlation between trend and sediment composition, which has changed in the last 20 years due to the climate change, is established.
"For the first time, in addition to detailed trend analysis the bird counts for over 20 years are used to make more precise conclusion about the arrival time and spatial distribution of flyway birds in the Wadden Sea area. Even if the results indicate that some of the reasons for the negative trends could be found in the Wadden Sea area or in climate change, the causes must be also sought for and acted upon along the entire bird flyways. In preparation is a federally funded three-year project that aims at improvement of the local expertise in the field of bird conservation, which will be implemented in West Africa," says Jens Enemark, Head of the International Wadden Sea Secretariat, Wilhelmshaven.
For over 20 years, the Wadden Sea Secretariat together with the Joint Monitoring Group of Migratory Birds (JMMB) coordinates a program for counting of migratory birds in the Wadden Sea. The commitment of many volunteer bird counters and professional ornithologists around the Wadden Sea enables multiple coordinated censuses every year, on the basic of which the trend calculations are built.
Detailed information on the trends of 34 bird figures resting in the Wadden Sea can be found at www.waddensea-secretariat.org. All the bird trends in the Wadden Sea are presented graphically on the website together with the summary tables trends. The trends for 26 bird species of the Wadden Sea are also presented on the website.
Contact person: Gerold Lüerßen
E-Mail: luerssen@waddensea-secretariat.org
Tel.: 04421 9108 16
Mobile: 0170 22 56 342
