The European White Stork is a stately wading predatory bird, which often nests in proximity to human settlements, and correspondingly, appears richly in human legend throughout recorded history. The population of this species has declined since the year 1900, primarily in Western Europe; this trend is chiefly due to relentless conversion of open land to agricultural uses in Europe, but also relates to surface water supply reduction in the African wintering range. Its migratory patterns reveal a distinct divide, owing to its preference to avoid long sea crossings. C. ciconia is the national bird of Lithuania, and in a number of European cultures is thought to bring harmony to families; the European White Stork is historically associated with the birth of babies in many regions of Europe.
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Breeding pair atop their nest near Ķemeri National Park, Latvia. @ C.Michael Hogan |
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DISTRIBUTION
C. Ciconia breeds from Western Europe to the western part of Russia, southern Kazakhstan and thence south to Greece, Turkey and Iran. Furthermore it breeds as far southwest as the Iberian Peninsula including both Spain and Portugal, and into northwest Africa, especially Morocco; however, the breeding areas are severely fragmented within those large geographic outlines. Consequently, the largest breeding populations are found in only a small number of countries including, Belarus, Ukraine, Poland, Bulgaria, Spain, Portugal and the Baltic countries. Wintering occurs as far south as sub-Saharan Africa and as far east as eastern China. Its long winter migration can reach as far as South Africa, and occasionally breeding will take place that far south. Birds migrate in irregularly shaped flocks which can be sizable, and sometimes will pause migration when a plague of locusts is occurring in East Africa.
A clear migratory divide exists for this species, which eschews long flights over open seas, (Perrins, Lebreton and Hirons) partly due to its reliance on atmospheric thermals, which occur over land. Thus the principal migration routes include either the Straits of Gibraltar or the Bosphorus, noting that some birds choose to winter in southern Europe as well.
MORPHOLOGY
C. circonia can attain a length of 115 centimetres and a body mass of three to four kilograms. (Perrins, Attenborough and Arlot) Wingspan can be as great as 1.65 metres. Legs and long powerful sharply pointed bill are bright salmon-red in colour, with mostly white feathers, save for the jet-black scapulars, greater wing-coverts and quills. (Sharpe) Vocalisation is typically absent except loud bill-clappering when sitting atop nests; additionally, hissing and coughing sounds are occasionally vocalised.
REPRODUCTION
Massive nests measuring 1.9 metres across are constructed high atop posts, trees or buildings, made from sticks and twigs; it is common to see nest sites near human habitation areas, but most often in open country rather than in forests. When the adult pair meet at the nest, they often engage in a ritual of bowing, followed by tipping their heads far back and producing their characteristic loud bill clattering. Typically three to five glossy white eggs are laid in each breeding cycle; these elliptically shaped eggs are about seven centimetres in length, coarse in exterior texture and dotted with small pores. (Oates, Reid and Ogilvie-Grant) Both male and female incubate the eggs for a total period of about 33 days. Initially for the first ten days, chicks are fed regurgitated food. The chicks typically evacuate their nest at age 60 days. (Burton) European White Storks mate for life and re-use the same nest from one year to the next. Lifespan in the wild can be as great as 25 years.
BEHAVIOUR
In flight the bird's head and neck are prominently extended. (Peterson, Mountfort and Hollum) Flying is somewhat slow and appears laboured, although it can soar on atmospheric thermals to magnify its own propulsion power. Terrestrially C. ciconia moves very deliberately as it stalks prey, and lunges in its final attack mode. Nesting occurs in farmlands and villages across Northern Europe; surprisingly I observed nests in larger cities such as Marrakech, Morocco in the midst of busy commercial districts.
HABITAT AND ECOLOGY
The European White Stork is most commonly found in damp and marshy areas, but often on drier grassy prairies; a typical nesting habitat is on the broad low-lying grasslands in the Baltic countries, where proximity exists to human settlements as well as marshy ecosytems. Moreover, it feeds chiefly on a variety of amphibians, arthropods and small mammals. Specific prey categories include lizards, grasshoppers, locusts, snails, mice, voles, and small fish. Very often C. ciconia is seen wading in shallow marshes in pursuit of its prey
CONSERVATION
Although the species breeding range is expansive, this area has contracted during the twentiieth century, the European White Stork no longer nesting in southern Sweden or in Switzerland. The chief reason for species decline is ongoing intensification of modern agriculture, steadily depriving C. ciconia of marshy habitat as natural wetlands are converted to food production to meet demand of the expanding human population. Besides the main reason of agricultural expansion as a factor for species decline, other factors contributory to excessive mortality are known to be expanded use of pesticides to support agriculture in the 1900s and also the increase of stork collisions with power lines during this period.
The species population decline is most dramatic among the western species among the migration divide; for example, European White Stork breeding populations in the Netherlands declined over ninety percent from the 1930s to 1980s. Further exacerbation of the western branch of the species decline is reduction of West African locust populations in the Western Sahel; these locust shortages have become more pronounced with increasing frequency of drought and shortage of surface water in the Western Sahel progressively during the 1900s and continuing to the present. I noted similar declines in surface waters in Morocco, with inexorable pressure from human diversion and use of surface waters, resulting in depauperate supplies for migrating birds. My observations in Morocco included measurement of water quality, river flow, lake levels and examination of historical river flow records in addition to review of historical aerial photographs. Since the late 1980s some local bird populations have made a mild rebound due to certain European wetland conservation efforts.
Rights Holder: C. Michael Hogan
Bibliographic Citation: C. Michael Hogan. 2009.
''Species account for Ciconia ciconia". Globaltwitcher. ed. N.Stromberg
