White Stork Conservation

To provide nesting sites for white storks in Switzerland

 

Without human impact, Europe - except for high mountain ranges and the Nordic tundra - would essentially be covered by boreal forest. The conversion of forest into agricultural land created new habitats for grassland species migrating from Asia, such as the souslik, hamster, brown hare, partridge, common quail, corn crake, field lark and so on. However, what had been created by traditional farming was largely destroyed by modern agriculture during the 19th and 20th century. One species, which particularly suffered from the effects of intensified agriculture and the related drainage of wetlands, was the white stork, Ciconia ciconia. This species, although globally not threatened, declined in Northern, Central and Western Europe mainly from 1850 on, and disappeared subsequently from many parts of its former range. E.g., the stork became extinct as a breeding species in Belgium (1895), Sweden (1955) and the Netherlands (1984). In Denmark, which had an estimated population of 10'000 pairs in 1850, only 14 pairs were left by 1985. In Switzerland, where many wetlands had to be drained and agriculture intensified to ensure the survival of the densely populated landlocked country during World War II (1939-45), the last pair of the original wild population nested in the village of Neuenkirch in 1949, i.e. the stork was extinct as a breeding species in 1950.

 

Fortunately, Max Bloesch (1908-1997), then a young teacher of the city of Solothurn, after an encounter with one of the last breeding pairs nesting and rearing its young on the roof of an old farmhouse, got hooked on the species, documented its decline and initiated a reintroduction programme. He established a reintroduction centre in Altreu, a small village on the Aare River close to Solothurn, which he populated, in 1948, with a few storks from Alsace. Recognising that he could not reach his goal with the few birds available from within Europe, he went, in 1955, on an expedition to Algeria and brought 36 fledglings back to Switzerland. 24 of these birds were released in nests in Altreu, the Goldau Landscape and Animal Park, and two other sites. The remainders were kept in aviaries for breeding. Other expeditions followed in 1959, 60 and 61, and in total close to 300 storks were imported to Switzerland.

 

Fortunately, Max Bloesch was not too impressed, and the birds themselves unaware, of all the conservation experts and other sceptics claiming that a reintroduction programme based on non-migrating storks from North Africa would inevitably fail. While some storks stayed during winter in Switzerland, many of them migrated along the western fly-way to Spain and further into Africa as far as Mali and, in 1960, the first free-ranging pair bred at Altreu just outside the reintroduction centre. Successively the number of breeding pairs at Altreu increased and stabilised at about 40. From 1966 on, 23 additional breeding and reintroduction centres were established and the population grew continuously. In 1976, Max Bloesch founded an NGO to ensure the long-term existence of the programme. In 1994, this "Swiss Society for the White Stork" (now called "Storch Schweiz - Cigogne Suisse", decided to no longer breed storks in aviaries, and to phase out the supplementary feeding of the wild storks. From then on, the breeding and reintroduction centres have been successively converted into information centres and activities shifted to monitoring the storks on their migration and securing feeding grounds in Switzerland.

 

In 2004, altogether 198 breeding pairs were counted on the Swiss territory, 116 of which successfully reared a total of 257 young. 225 adults (57.6%) migrated to their traditional wintering grounds in the Iberian Peninsula, North and West Africa. Of course national boundaries are meaningless for storks, and Swiss storks mix with the reintroduced storks in Southern Germany where, in 2004, 35 birds originating from the Swiss programme reared 80 offspring. Several Swiss birds also live in Alsace and Lorraine.

 

 In 1977, a wild pair from the Altreu reintroduction programme joined the group of pinioned zoo storks at Lange Erlen Animal Park, Basel, built a nest in a tree and successfully raised 2 offspring. In 1979, a first wild pair settled at Silberweide Animal Park near Zurich. In 1982, the same event happened at Basel Zoo, and in 1992 at Zurich Zoo. The park landscape of the Swiss zoos with many large old trees proved to be an ideal breeding habitat for the storks, with feeding grounds on agricultural land are close to all.


By 2006 the zoo colonies had grown to 18 pairs in Basel, 14 in Lange Erlen, and 6 in Zurich, representing 17 % of the Swiss breeding population. Breeding success at the zoos is, in some years, clearly above average: 85 of the 257 young wild storks which left the nest in 2004, and 65 of 344 in 2005 were bred at the zoo colonies (33 and 18 % respectively). Altogether, more than 515 wild storks have left the nests at Basel Zoo, more than 258 at Lange Erlen Animal Park, and more than 94 at Zurich Zoo. There is also still a breeding pair at Silberweide although the animal park is no longer operating as such.


Pinioning is no longer practised at the three zoos, and the storks are no longer fed, although they may profit to some extent from feed provided to other species. A high percentage of the storks migrate along the western flyway and hibernate somewhere between Spain and Mali. Mulhouse Zoo (France), only 25 km from Basel and a breeding site for wild storks as well, has become a popular intermediate stop for storks migrating from Germany and Northern Europe.


WAZA Conservation Project 05009 is implemented by the Basel Zoo, Zurich Zoo and Lange Erlen Animal Park in support of the reintroduction programme of "Storch Schweiz - Cigogne Suisse". Members of the World Association of Zoos and Aquariums cooperate also in other European countries with authorities and NGOs with a view of restoring or maintaining white stork populations.

 

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