Biology
White stork
- Subject to strict protection, pursuant to the Regulation of the Minister of Environment of 12 October 2011 on the protection of animal species (Journal of Laws of 2011, No. 237, item. 1419), species in need of active protection.
2. The Polish Red Data Book of Animals - least concern species (LC) - The Birds Directive - Annex I
- BirdLife International – SPEC 2
- The Berne Convention - Annex II
- The Bonn Convention - Annex II
- IUCN – least concern
POPULATION DYNAMICS
Since the mid-nineteenth century, there was a period of shrinking of the breeding area and sometimes a dramatic decline in the number of white storks. After a clear improvement of the situation at the beginning of the twentieth century, again there was a significant decline, with the absolute minimum in the years 1928-1929. However, in a later period, especially in 1934, the situation improved. In the western part of Central Europe, after several years of fairly intensive growth in numbers, there was another setback, caused by, among others, the reduction of feeding areas. In Poland, in the last few decades, the population has been increasing (Guziak & Jakubiec 2006), but the Monitoring of Flagship Species of Birds (MFGP) led by the Chief Inspectorate of Environmental Protection shows that the population has been decreasing over the past 14 years by 0.4% per year. This is also confirmed by data from the study “Prioritised action framework for Natura 2000 network for Long-term Financing Programme of the EU in the years 2014-2020” (PAF), which indicate a downward trend. This is also confirmed by the results of the VII International White Stork Census - population decline compared to 2004 by approx. 30%.
ECOLOGY
The white stork nests almost exclusively within human settlements, on structures towering over the nearest surroundings (buildings, trees, chimneys and power poles). The birds feed mainly on permanent grassland: meadows and pastures, crops of legumes (clover, alfalfa), abutments and in streams, shallow rivers, backwaters, drainage ditches, fish ponds and swamps. Storks rarely look for food in the fields, usually during ploughing and other field works. The number of local breeding pairs is usually positively correlated with the area of permanent grasslands in the neighbourhood. White storks can breed in colonies with nests only a few meters of distance between each another. On the other hand, a single nesting pair often chases away other individuals trying to settle nearby. It usually feeds within a few kilometres from the nest. Observations showed that in the first 3 weeks of life of the chicks, the birds usually feed 1.5-3 km from the nest (Dziewiaty & Schulz, 1998), and with further increase in demand for food, adult birds penetrate also more remote areas. The white stork's nest is very large and is usually clearly visible. If it’s built from scratch, it is initially approx. 80 cm in outer diameter and 30 cm in height. One lay is 2-6 eggs.
THE WHITE STORK AS AN EXAMPLE OF ECOSYSTEM SERVICES
The white stork has long been considered an umbrella species, which means that its protection is beneficial to many other co-occurring species and their habitats. In a study conducted in western Poland, it has been shown that agricultural areas around occupied stork nests were characterized by a greater diversity of bird species than the areas that were left by storks. This confirmed the hypothesis (Solon 2008), that the stork is a good indicator of biodiversity and an umbrella species.
Furthermore, storks in territories where there are more other species of birds, delivered more young than storks occupying territories with fewer species found. This is caused by the greater number of habitats in the territories occupied by the stork, where there is also a greater abundance of food (Tobółka et al. 2012). In the nests of the white stork more than 10 nesting species of birds have been found: sparrow, tree sparrow, Spanish sparrow, great tit, common reed bunting, common redstart, starling, white wagtail, blackbird, collared dove, common wood pigeon, jackdaw and magpie (Indykiewicz 1991, 1998, 2006; Bochenski, 2005; Kosicki et al. 2007; Mascara & Sarà 2010 A. Zbyryt E. Kapowicz - unpublished data), and sometimes mallard and common kestrel (Połutrenko 1996, Brix 1999, P. Białomyzy - unpublished data). In addition, the stork's nest provides shelter during the winter and a convenient place to spend the night in adverse weather conditions for sparrows, tree sparrows and starlings (Tobółka 2007 2011).
“THE NATIONAL BIRD”
Poland is considered the homeland of storks, and this bird is deemed one of the national symbols recognized in the country and abroad (especially in Western Europe). The features of the stork that predestine it to be a national symbol is the coloration consistent with the national colours, as well as the large body size and kind of dignity expressed in its appearance and movements. The following are also important: large number and widespread recognition among people, convergence of occupied habitats (nesting in settlements, feeding in agricultural landscape), as well as rooting in the tradition, assigning features to storks, symbols desired and accepted by people, although not necessarily in line with biological knowledge, i.e. wisdom, caring, faithfulness, nobility, bringing happiness and children.
Foreigners identify Poland as a country of storks, which also raises positive associations. Among potential tourists and also investors, Poland is perceived as a country of an idyllic life and beautiful landscapes (Florek & Jankowska 2012), and although it consists of many symbols, the stork, which constitutes a direct link of nature with human, has a special place among them. Information about storks is among the most searched on the Internet and a Google search for 30 November 2012 gave about 3.6 million references to the word “stork”. Such a high result clearly indicates that this is one of the most popular species of birds (Żmihorski et al. 2013). The white stork is a very common motif in Polish art. The image of the stork is used as a model for many popular products. Additionally, the white stork is one of the most popular species, at the nest of which webcams are mounted. The most famous of them (in Przygodzice), in the period 2009-2012, for many days at a time, occupied third place in the Top 1000 Birding ranking, which includes more than a thousand cameras showing birds, competing, for instance, with the websites of the world's largest ornithological organizations (BTO, RSPB, etc.) and large commercial companies engaged in ornithological tourism.