History of its decline

The White Stork used to be widely distributed in all of Europe. At the beginning of the 20th century, 150 nesting pairs were counted in Switzerland!

Since then, White Storks became rare in all Europe. Hunting, mainly in France, was probably one of the main causes of the decline in the White Stork populations.

In Switzerland:

1900 about 140 nesting pairs

1920 about 50 nesting pairs

1930 about 16 nesting pairs

1949 1 nesting pair

1950 0 nesting pair

Since 1948, in Altreu (Canton of Solothurn), Max Bloesch tried to reintroduce White Storks from Alsace and from Eastern Europe. Between 1955 and 1961, 262 young White Storks from Algeria were introduced into Switzerland. In 1960, a pair nested again in the wild, for the first time in Switzerland, and since then the population increased.

1973 26 nesting pairs

1983 90 nesting pairs

1993 145 nesting pairs

1998 167 nesting pairs

only 120 pairs reproduced

How can we explain the evolution of the White Stork population?

The changes in the White Stork population are very well known. Their numbers regressed until the 1980s, then increased afterwards because of several factors acting in combination.

The drainage of wetlands, the taming of rivers, and the intensification of agriculture associated with an increase in pesticide use were deleterious to the White Storks’ basic foods. Many White Storks were electrocuted by power lines. In the North African region of Sahel, a drought in the 1970s and the beginning of the 1980s caused an increase in mortality during the winter. Furthermore, White Storks have been (and, occasionally, are still today) hunted in western Africa as well as in France and in Spain.

The increase of the White Stork population in Western Europe was caused, not so much by the ecological restoration of nesting habitats (the success of its reproduction is still meager), but rather by changes that occured along their migration routes and in their wintering sites.

That increase can be attributed in part to the end of the drought in the Sahel region (since the mid 1980s). An increase was also noted in Spain, both in the numbers of nesting pairs and of individuals staying for the winter. In new irrigation fields, an imported species of crawfish has spread and has become a main prey for the storks. In addition, the increased number of garbage dumps allowed storks to reach new food resources year round. Without a doubt those changes had an influences on the stork population in Central Europe.

Development of European White Stork populations

Interpretation of symbols:

Arrow pointing up: increasing number of nesting pairs

Arrow pointing down: decreasing number of nesting pairs

Square: the number of nesting pairs is stable (or more or less stable)

Star: the number of nesting pairs is very low

Both maps were taken from:

Schulz, H.(1999) : Weissstroch im Aufwind ?- White Storks on the up ?

Proceedings of the International Symposium on the White Stork, Hamburg 1996. NABU, Bonn, 335-350. http://come.to/ciconia