White Stork

From SongbirdReMixWiki

Jump to: navigation, search

Image:Whitestork.jpg

Common Name: White Stork
Scientific Name: Ciconia ciconia

Size: 40-50 inches (100-125 cm)

Habitat: Europe, Asia & Africa; breeding in the warmer parts of Europe (north to Estonia), northwest Africa, and southwest Asia (east to southern Kazakhstan). It is a strong migrant, wintering mainly in tropical Africa, down to the south of South Africa, and also in the Indian subcontinent.

Status: Least Concern. Global Population: 500,000 - 520,000. The overall population of White Storks has declined steadily over the last half century. The decline in Western Europe has been the most pronounced. Pollution, pesticides and wetlands drainage have severely reduced suitable foraging habitat across the breeding range. Storks no longer breed in southern Sweden, Switzerland, western France, Belgium or southern Greece. In The Netherlands the number of breeding pairs has declined from 500 in 1910 to 5 in 1985. Denmark was home to 4000 pairs in 1890, but only 12 in 1989. Captive propagation and reintroduction efforts have been hampered by their tendency to produce overly tame birds, which over-winter in Europe without migrating normally.

The White Stork is one of the species to protected by the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA).

Diet: Insects, frogs, toads, tadpoles, fish, rodents, snakes, lizards, earthworms, mollusks, crustaceans, and, rarely, the chicks or eggs of ground-nesting birds. Foraging storks search for prey visually while walking deliberately with bill pointed toward the ground. When prey is spotted, they cock their necks back, then jab the bill forward to grasp their victim. Wintering birds in Africa will congregate around the edges of grass-fires to capture small prey fleeing the flames.

Nesting: White Storks form loose informal colonies while breeding. Several pairs may nest closely together within sight and sound of one another while appearing completely oblivious to their neighbors. Though storks form monogamous pairs for the duration of the breeding season, they do not migrate or over-winter together. If the same pair reforms in successive years it is largely due to their strong attachment to their nest site.

Males usually arrive at the nest-site first. A male will greet a newly arriving female with the Head-Shaking Crouch display, as he lowers himself on the nest into the incubating posture, erects his neck ruff and shakes his head from side to side. If the male accepts the new arrival as his mate they will cement their pair bond with an Up-Down display. In this display the birds hold their wings away from their sides and pump their heads up and down. This is often accompanied by bill-clattering. Shorter courtships may indicate that the male and female were paired in previous years.

Nests are huge, bulky affairs constructed of branches and sticks and lined with twigs, grasses, sod, rags, and paper. Though they may be reused year after year, breeding birds will add to the structure each season. Particularly old nests have grown to over 2 m in diameter and nearly 3 m in depth. Some nests have been in continuous use for hundreds of years. Both sexes participate in nest construction with the male bringing most of the material. Completion of the structure is often signaled by the addition of one leafy branch to the edge of the nest.

European Storks have been building their nests on man-made structures since the Middle Ages. They can be found on rooftops, towers, chimneys, telephone-poles, walls, haystacks, and specially constructed nest towers. Many homeowners will add embellishments such as wooden wagon wheels to old chimneys to encourage storks to nest on their houses. Nests can also be found in trees, on cliff-ledges, or occasionally on the ground.

The female usually lays 3-5 eggs, more rarely up to seven. Parents share incubation duties for 33-34 days. Young chicks are covered with white down and have black bills. Both parents feed the young on the nest until they fledge at 8-9 weeks of age. Fledglings may continue to return to the nest site each evening to beg for food from their parents. Young birds reach sexual maturity in their fourth year. Banding records indicate that wild birds can live and reproduce successfully past 30 years of age.

Cool Facts: The legend that the European White Stork brings babies is believed to have originated in northern Germany, perhaps because they arrived back in Europe on fairly predictable dates and almost exactly 9 months after the previous mid-summer. Northern Europeans of Teutonic ancestry encouraged storks to nest on their homes hoping they would bring fertility and prosperity. This tradition of welcome and protection did not exist in the portions of France where the White Stork disappeared first.

It walks slowly and steadily on the ground. Like all storks (with the exception of the Leptoptilos genus), it flies with its neck outstretched.

In the 1980’s, the population of this "iconic emblem of Alsace", the bird revered for bringing fertility and luck to any home upon which it nested, had fallen to fewer than nine pairs in the entire upper Rhine River Valley, an area closely identified with the White Stork for centuries. Conservation efforts there, particularly by the Association for the Protection and Reintroduction of Storks in Alsace and Lorraine, have successfully increased the population of birds to 270 pairs.

Storks are large birds that rely heavily on energy efficient soaring flight during migration. Soaring requires the presence of thermal air currents that are not found over water. White Storks are therefore reluctant to fly across large bodies of water such as the Mediterranean Sea to reach their wintering grounds in tropical Africa. They solve this problem by having the bulk of the European population split into two distinct migratory routes. Western birds cross the Mediterranean at the Straits of Gibraltar, while most of the eastern birds cross the Bosporus and circle around the Mediterranean through the Middle East. Migration is highly synchronized and flocks contain as many as 11,000 individuals. Birds migrating from Denmark to South Africa and back again may cover a total distance of 20,000 km. Small numbers of birds cross the Mediterranean directly by flying south from the southern tips of Italy and Greece. Some western European White Storks join the Asiatic subspecies C. ciconia asiatica to winter in India.


Found in Songbird ReMix Shorebirds Volume I

Personal tools