The project

SOS Stork – White Stork migration in the face of change

A project by: Stork Switzerland (Managing director: Peter Enggist)
Project leader: Dr. Holger Schulz

The migration behaviour of the western population of White Storks (Ciconia ciconia) has changed: a large proportion of these birds do not migrate down to West Africa any more as they used to do in the past – they now overwinter in the south of Spain.

When “Stork Switzerland”, the Swiss Association for the Protection of the White Stork, carried out their large satellite telemetry project “SOS Stork” in 2000 and 2001, which came about as a result of the initiative by Peter Enggist (Managing Director), it was found that almost half the Swiss storks “get stuck” in the south of Spain. This hasn’t changed. Many thousands of “westward-moving” White Storks end their migration in southern Spain, where they find food in rice fields and, above all, on large, open waste disposal sites.

According to an EU guideline from 1999, which is supposed to be implemented by the year 2016, the organic part of the waste deposited in EU countries has to be gradually reduced to 3%. In simple terms, this means: leftover food and similar household waste will have to be sorted out and composted, burnt or used in biogas sites. What impact will the disappearance of the food-source “waste” have on the storks that overwinter in Spain? To what extent has the EU guideline already been implemented? What does the timescale look like for the implementation of the guideline on the waste disposal sites in the south of Spain? What is the importance of waste disposal sites for the storks in comparison with other food resources in the region?

We also do not have an answer so far to the question of what is the trigger for the altered migration behaviour. Might the “settlement projects” in the past be responsible? Half a century ago, White Storks from North Africa were “imported” into Switzerland and indirectly also into other countries in Western Europe in order to build up the stork populations again – which, until then, had become almost extinct. The genes of these birds possibly are still present in many “European” storks. Does this perhaps have an influence on the route and distance of their migration? What role does climate change play? Many questions that, with the continuation of the successful project “SOS Stork”, ought to be answered.  

As was the case with the first part of the project “SOS Stork”, continuation with its new focuses will be carried out under the management of stork expert Dr. Holger Schulz in collaboration with Peter Enggist. In co-operation with partners from other European countries and experts on specialist examinations (e.g. genetic analysis), detailed examinations will be carried out in the following years on the storks that overwinter in the south of Spain.