Black stork

The black stork, known scientifically as *Ciconia nigra*, is a large and striking bird belonging to the stork family, Ciconiidae.

This species is recognized by its dark plumage, which features a purplish green sheen.

This iridescent effect is most noticeable in new feathers following the spring moulting season. The bird also possesses white underparts, including the lower breast, belly, and undertail coverts. It is easily identified by its long red legs and a long, pointed red beak.

Unlike the more common white stork, the black stork is a shy and wary species. It prefers to live alone or in pairs, often seeking out quiet, marshy habitats.

To find food, the black stork utilizes a specific hunting method in shallow waters. It wades slowly and steadily through rivers, ponds, or estuaries to stalk its prey. This patient movement allows the bird to catch small fish, insects, and various amphibians.

During the breeding season, these birds require specific nesting sites to raise their young. They typically build nests in large forest trees, which can be deciduous or coniferous. In mountainous regions, they may choose large boulders or overhanging ledges. The female lays between two and five greyish-white eggs. Both parents share the responsibility of incubation, which lasts between 32 and 38 days. Once the chicks hatch, they remain in the nest for a fledging period of 60 to 71 days.

Many populations of the black stork are long-distance migrants. These birds travel vast distances between their summer breeding grounds and wintering sites. European populations often fly to tropical Sub-Saharan Africa during the winter. Asian populations generally migrate to the Indian subcontinent.

An isolated group of black storks in Southern Africa is non-migratory, meaning they stay in one area. Because black storks are broad-winged soaring birds, they rely on thermals to assist their flight. Thermals are rising columns of warm air that provide lift. However, since thermals only form over land, the birds must navigate carefully around large bodies of water.

Migration routes are carefully chosen to avoid crossing broad expanses of the Mediterranean Sea. One group travels via the western route, passing through the Strait of Gibraltar. Another group utilizes the eastern route, flying through the Levant or the Sinai. Satellite tracking has revealed the significant time these journeys require. The western route takes an average of 37 days to complete. In contrast, the eastern route takes an average of 80 days. These birds often stop at specific locations, such as various national parks in Spain, to rest during their long travels.

History shows that scientists have studied the black stork for centuries. In the 17th century, the English naturalist Francis Willughby wrote about the species after seeing one in Frankfurt. The Swedish zoologist Carl Linnaeus later provided a formal description in the 10th edition of *Systema Naturae* in 1758. He originally used the binomial name *Ardea nigra*. Two years later, the French zoologist Mathurin Jacques Brisson moved the species to the genus *Ciconia*. This genus includes seven extant species characterized by straight bills and black and white plumage. In 1997, researcher Beth Slikas used DNA–DNA hybridization and mitochondrial cytochrome b DNA analysis to study their lineage. Her research found that the black stork is a basal species, meaning it is an early offshoot of the *Ciconia* genus.

Today, the black stork's population status is complex and varies by region. The International Union for Conservation of Nature lists the species as a "least concern," but its actual status remains uncertain. The bird is not abundant anywhere, despite having a very wide range. In some areas, such as India, China, and parts of Western Europe, the population appears to be declining. Conversely, numbers are increasing in the Iberian Peninsula, with an estimate of 405 to 483 pairs in 2006. Various conservation efforts are in place to protect them. These include the Conservation Action Plan for African black storks by Wetlands International. The species is also protected by international agreements like the African-Eurasian Waterbird Agreement.

Understanding the black stork helps us see how different ecosystems are connected. Their survival depends on healthy wetlands, forests, and migratory corridors. For example, the draining of wetlands in Iran has caused population declines there. Similarly, pesticide use has threatened birdlife in areas like Doñana in Spain. By protecting these specific habitats, we help ensure the survival of the entire migratory system. The black stork serves as a vital link between the forests of Europe and Asia and the tropical regions of Africa and India.