1st Interim Report 2013

We have noticed for years that 50% of the westward-moving storks (Ciconia ciconia) of the northwest population have altered their migration behaviour significantly. A high percentage of these birds no longer fly to West Africa but instead overwinter in the south of Spain. The birds stay there to find food, mainly on large open waste disposal sites.

The question what triggers the altered migration behaviour has not been answered yet. Could past “reintroduction projects” be responsible for it? Half a century ago, white storks from North Africa were “imported” into Switzerland and indirectly also other countries in Western Europe to build up a population again that had almost become extinct by that time. The genes of the “reintroduction” birds can probably be found in many “European” storks. Do the genes perhaps have an influence on the route and distance of stork migration? What role does climate change play? The project “SOS Stork migration in the face of change” aims to address these questions.

International cooperation, January to October 2011

Besides carrying out field work during the research trip in Spain, contacts with potential project partners were established. The SEO (Spanish Ornithologists Association) is interested in a collaboration as project partner and will be of great importance when doing work in Spain, e.g. by providing support with data recording, with applications for authorisation of admission to the disposal sites, etc. Cooperation has also been initiated with the experts in the European stork village Malpartida de Caceres. Further contacts, for example with stork conservation experts in France, have also been made. The goal is to expand the project internationally, in collaboration with experts from Spain, France and all other countries in the distribution area of the western White Stork population.

Satellite tracking, July to October 2011

In the summer of 2011, five young storks were equipped with satellite transmitters in Switzerland in order to verify what significance the disposal sites really have for the Swiss storks. Unfortunately, three of the storks equipped with transmitters dropped out as early as August and September 2011. The maps with location changes for the individual storks were up-dated on a regular basis and can be looked at under the menue point “Satellite tracking” or the following links:

>> Bruno
>> Dani
>> Amelios
>> Düschess
>> Sämi

Stork “Bruno”:
In Spain, rest at various disposal sites for several days each time. At the beginning of October, arrival in Morocco; there, close to the city of Kenitra, north of Rabat, stay on a disposal site. Last position data on 10.10.2011. Probably malfunction of the transmitter (technical defect?).

Stork “Dani”:
Migration through France and over the eastern edge of the Pyrenees. Throughout September and until 10.10.2011, stay at the disposal site Montoliu close to Lerida. On 11th October, continuation of his flight to Zaragoza in the Ebro valley; stay there at a large disposal site as well.

Stork “Amelios”:
Migration through France and over the eastern edge of the Pyrenees. Last position data at the end of August 2011, just south of the French-Spanish border. Probably malfunction of the transmitter (technical defect?)

Stork “Düschess”:
As early as four weeks after being equipped with a transmitter, on 4th August 2011, the bird was found dead close to the location where it had been fitted with the transmitter.

Stork “Sämi”:
During his migration through Spain, rest at various disposal sites, for several days each time. Beginning of October, crossing Strait of Gibraltar and speedy continuation of his flight through Morocco to the south. At present (20.10.2011) in border area Mauritania/Senegal, close to the Senegal river. 

Despite the breakdown so far of three transmitters, the results achieved by satellite tracking now already confirm the importance of waste disposal sites on the western migration route. The three transmitting storks that flew through Spain, in a sense, “brachiated through” from disposal site to disposal site in a southern direction. There were longer stays almost only at disposal sites. Apart from the already known and above-mentioned disposal sites, we were able to detect further disposal sites by means of the GPS co-ordinates of the birds. The rice fields by the Guadalquivir have again proved to be an important feeding site, as was the case back in 2000 and 2001. 

By now, there are thousands of precise pieces of information on location, the detailed evaluation of which supplied many insights on migration behaviour, habitat selection, range of activity, etc.

Field work, January until March 2011

After several months of planning and preparation, the actual project work began with an investigation and research trip in January 2011. For 7 weeks (19th January to 11th March 2011), the project leader travelled around Spain to determine the status quo, make first investigations and establish contact with potential project partners. Four waste disposal sites were visited. In summary, it can be said that on the one hand, the disposal sites still have a great significance for White Storks on the western flyway but, on the other hand, restructuring, i.e. reduction of the disposal of organic waste, has already begun. In only a few years’ time, the food-resource “waste” will probably have considerably decreased. 

Montoliu, close to Lerida/Catalonia:
For quite some time, reports have been pointing in the direction of the site Montoliu becoming increasingly important for the migrating White Storks. In March 2011, we were able to observe several hundreds of storks there. Yet, observers on-site report that, in winter time, thousands stay there. 

Dos Hermanas, close to Seville/Andalusia:
Several thousands of storks in January 2011. Authorisation for admission was unfortunately not granted. Observations made, however, suggest that the disposal site, with several thousands of storks spending their winter there in February 2011, has a similar importance to what it used to have back in the years 2000/2001. 

Miramundo, close to Medina Sidonia/Andalusia:
At the disposal site Miramundo, detailed examinations could be carried out in regard to both the behaviour of storks at the disposal sites, and the range of activity, roost behaviour, habitat selection, etc. In February, more than 2,000 to 3,000 storks were still present. Organic waste is still deposited there, but obviously less than 10 years ago.

Los Barrios, close to Algeciras/Andalusia:
No more than approx. 300 storks in February/March 2011. The old site, at which thousands of storks overwintered in the years 2000/2001, was no longer maintained. At the new disposal site nearby, waste is separated, processed and stored in halls or roofed places. It’s only on small surface areas that organic waste is still deposited.

The project

Project title: 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 during migration almost half the Swiss storks “get stuck” in the south of Spain. This hasn’t changed. Many thousands of  White Storks migrating on the western flyway end their migration in southern Spain, where they find food in rice fields and, above all, on large, open waste disposal site