White Stork

About the white stork

The white stork is a large bird in the stork family, Ciconiidae, with plumage that's mainly white apart from black on the wings. Adults have long red legs and long, pointed red beaks, measuring 100 to 115 cm (39–45 in) from beak tip to tail with a wingspan of 155 to 215 cm (61–85 in) and a weight of 2.3 to 4.5 kg (5.1–9.9 lb). Two subspecies exist, differing slightly in size: the nominate C. c. ciconia breeds from Europe to northwestern Africa and westernmost Asia and in southern Africa, wintering mainly south of the Sahara, while C. c. asiatica breeds in Turkestan and winters from Iran to India and is somewhat larger.

The sexes look identical apart from males averaging larger than females. The black flight feathers and wing coverts get their color from the pigment melanin, and long, shaggy breast feathers form a ruff used in courtship display. The bright red beak and legs come from carotenoids in the diet — in parts of Spain, that pigment traces to astaxanthin obtained from an introduced crayfish species, which is why nestlings there show brighter beak color than young storks elsewhere. Young birds hatch with sparse whitish down, replaced about a week later by denser woolly white down, and gain black scapulars and flight feathers by three weeks old. A chick's pinkish legs darken to greyish-black with age, and its black beak carries a brownish tip; full adult plumage and beak color arrive by the bird's second summer.

White storks fly with their necks stretched forward and legs trailing beyond a short tail, walking at a slow, steady pace with the neck upstretched, though they hunch their heads between their shoulders while resting. In flight, they can be confused with the yellow-billed stork, great white pelican, or Egyptian vulture, but differences in tail color, beak shape, leg length, and flock behavior distinguish them at a distance.

Behavior and diet

The white stork is a carnivore with a broad diet, eating insects, fish, amphibians, reptiles, small mammals, and small birds. Most food is taken from the ground among low vegetation or from shallow water. In parts of Poland, poor natural foraging grounds have pushed birds to seek food at rubbish dumps since 1999, and similar foraging at dumps has been reported in the Middle East, North Africa, and South Africa; anthropogenic litter turned up in the pellets of a third of breeding pairs studied in Poland, even where nests sat far from major dumps.

White storks are monogamous breeders. Both members of a pair build a large stick nest, which may be reused for several years, and each year the female lays a single clutch of usually four eggs. The eggs hatch asynchronously 33 to 34 days after laying, with both parents sharing incubation and feeding duties. Young leave the nest 58 to 64 days after hatching and continue receiving food from their parents for another 7 to 20 days.

The species migrates over long distances, leaving European breeding grounds in August and September for wintering grounds in African savanna from Kenya and Uganda south to South Africa's Cape Province, where flocks can exceed a thousand birds; some birds diverge west into Sudan, Chad, and as far as Nigeria. To avoid the long sea crossing of the Mediterranean, migrating birds detour via the Levant in the east or the Strait of Gibraltar in the west, since the thermals they rely on for soaring don't form over open water. Spring return trips average 49 days, compared with about 26 days for the autumn journey south, a difference attributed to tailwinds and the scarcity of food and water along the way, which pushes birds to fly faster through resource-poor stretches.

Range and habitat

The nominate subspecies breeds across a wide but disjunct range concentrated in the Iberian Peninsula and North Africa, and through much of eastern and central Europe and parts of western Asia, with a quarter of the world's population found in Poland. The much smaller asiatica population, roughly 1,450 birds, is confined to central Asia between the Aral Sea and Xinjiang in western China; the Xinjiang population is believed to have gone extinct around 1980. White storks prefer grassy meadows, farmland, and shallow wetlands, avoiding areas thick with tall grass and shrubs — a preference underscored by the population decline seen in Ukraine's Chernobyl area after farmland there reverted to tall grass and shrub following the 1986 nuclear accident.

The species benefited from human land clearing during the Middle Ages, spreading with new pastures and farmland as far north as Sweden, but changes in farming methods and industrialization drove a 19th- and 20th-century decline that erased it from parts of Europe. Reintroduction and conservation programs have since restored breeding populations in the Netherlands, Belgium, Switzerland, Sweden, and the United Kingdom, including a pair that bred in the U.K. in 2020 for the first time in over 600 years, as part of the West Sussex-based White Stork Project.

Conservation status

The white stork is rated Least Concern by the IUCN. It has few natural predators, though it can carry chewing lice and feather mites in its plumage, and its large nests host a diverse range of mesostigmatic mites. The species has also inspired many legends across its range, most famously the story of babies being delivered by storks. Its main historical setback came from 19th-century industrialization and shifting agricultural practices, which drove it out of many former breeding areas; current strongholds of the western population are in Portugal, Spain, Ukraine, and Poland, and targeted reintroduction programs have restored breeding in several countries where it had disappeared.