The White stork (Ciconia ciconia) is a large bird in the stork family, Ciconiidae. It eats a wide range of animal prey and takes most of its food from the ground. It does not pair for life but both members of the pair build a large stick nest, which may be used for several years. This conspicuous species has given rise to many legends across its range, of which the best-known is the story of babies being brought by storks.
White storks are long-legged wading birds. The sexes are identical in appearance, except that males are larger than females on average. The plumage is mainly white with black flight feathers and wing coverts; the black is caused by the pigment melanin. The breast feathers are long and shaggy forming a ruff which is used in some courtship displays. The irises are dull brown or grey, and the peri-orbital skin is black. The adult has a bright red beak and red legs, the colouration of which is derived from carotenoids in the diet. As with other storks, the wings are long and broad enabling the bird to soar. In flapping flight its wingbeats are slow and regular. It flies with its neck stretched forward and with its long legs extended well beyond the end of its short tail. It walks at a slow and steady pace with its neck upstretched. In contrast, it often hunches its head between its shoulders when resting. Upon hatching, the young White stork is partly covered with short, sparse, whitish down feathers. This early down is replaced about a week later with a denser coat of woolly white down. By three weeks, the young bird acquires black scapulars and flight feathers. On hatching the chick has pinkish legs, which turn to greyish-black as it ages. Its beak is black with a brownish tip. By the time it fledges, the juvenile bird's plumage is similar to that of the adult, though its black feathers are often tinged with brown, and its beak and legs are a duller brownish-red or orange. The beak is typically orange or red with a darker tip. The bills gain the adults' red colour the following summer, although the black tips persist in some individuals. Young storks adopt adult plumage by their second summer.
White storks are found across Europe, Asia Minor, the northern part of Africa, and the Middle East. By the winter months, they migrate into tropical regions of Africa, some parts of the Middle East, and the Indian subcontinent. White storks prefer to feed in grassy meadows, agricultural fields, pastures, steppes, savannas, and shallow wetlands avoiding areas overgrown with tall grass and shrubs. Breeding grounds include open grasslands, particularly grassy areas which are wet or periodically flooded, and less in areas with taller vegetation cover such as forest and shrubland.
White storks are gregarious and non-territorial birds. They typically gather into loosely structured groups. During the breeding season, they nest in small colonies, constructing the nests far from each other. Non-breeding birds form groups of 40-50 individuals. During their annual migration and in their winter range, the birds gather into large flocks of hundreds or thousands of storks. White storks prefer to forage in meadows that are within roughly 5 km (3 mi) of their nest and sites where the vegetation is shorter so that their prey is more accessible. They hunt mainly during the day, swallowing small prey whole, but killing and breaking apart larger prey before swallowing. In order to communicate with each other, White storks use various calls. Their main sound is noisy bill-clattering, which has been likened to distant machine gun fire. The only vocal sound adult birds generate is a weak barely audible hiss; however, young birds can generate a harsh hiss, various cheeping sounds, and a cat-like mew they use to beg for food. Like the adults, young also clatter their beaks.
Bing carnivores, White storks consume various animal species, found in shallow water and on the ground. They eat fish, frogs, snakes, rodents, lizards, crustaceans, toads, tadpoles, spiders, scorpions as well as small mammals. They will also eat chicks and eggs of bird species, nesting on the ground.
These birds have a monogamous system, mating once in a lifetime. The mating season takes place in spring, typically from March to April. White storks return to the breeding grounds a few days prior to females, enlarging the nests, left from the previous season. Courtship rituals include soft cooing calls as well as loud warnings to scare away intruders. After mating, the female lays 2-5 eggs with intervals of 2 days. Both parents take part in the incubation process, which lasts 33-34 days. When the chicks hatch out, both the male and the female feed the young by rotation. The chicks fledge, reaching the age of 58-64 days. Then, around 7-20 days after fledging, they become independent. White storks start breeding at the age of 3-5 years.
This wader suffers from the alteration of its wetland habitat. During the winter, the birds are affected by desertification, drought, and the use of pesticides, which greatly reduce available prey items, causing food shortages. Nesting on buildings, the birds suffer from the reduction of suitable nest-sites due to new architectural solutions. In some areas of their range, White storks occasionally collide with electric wires. In addition, the birds are hunted for sport and food, usually during their migration into their wintering grounds.
According to the IUCN Red List, the overall population of the White stork is increasing and estimated at 700,000-704,000 individuals. Meanwhile, the population in Europe is estimated between 224,000 and 247,000 pairs. On the IUCN Red List, the species is classified as Least Concern (LC).
Preying upon various animals, White storks control the number of these species’ populations. These birds are also largely associated with humans. Thus, in agricultural lands, they benefit farmers by killing pests, while in the Palearctic ecozone of their range, storks inhabit areas, chosen by humans as agricultural lands.