Poster-bird 2021: Black Stork
Poster-bird 2021: Black Stork
This year’s poster-bird is a regular at the Festival: the unmistakable Black Stork (Ciconia nigra). Festival-goers usually spot it as a black shape with a long neck, soaring high overhead.
Its sillouette looks similar to the better-known White Stork, but if lighting allows you to see its colours clearly, there’s no mistaking it. The Black Stork, as its name implies, is almost completely black: the feathers on its head, neck, rump and wings are black with a metallic purple and green sheen. Seen from below, in flight, you can tell that the white on its belly extends only to a triangle in each armpit; a marked difference from the White Stork, whose wings are white with black only at the tips.
Black Storks use their colour contrast to communicate amongst themselves: they raise their head and stretch out their neck, showing off their white underside, in a display that becomes vigorous in confrontational situations.
Adult Black Storks have red beak and legs, but unlike White Storks, the juveniles’ beak and legs are green.
Shier than White Storks, Black Storks are usually seen alone or in pairs (during breeding season), but from August to September, when they migrate to Africa, they may gather in flocks of up to 100 birds. This is when they are easiest to spot, and Sagres is a particularly good vantage point from which to do so, precisely around the Festival’s dates. At this time, Black Storks from central Europe congregate here, in search of passage to Africa. Since they need thermals to soar, and these hot air currents only form over land, these birds tend to cross the Mediterranean at its narrowest point, at Gibraltar.
Although some Black Storks overwinter in the south of Portugal, most fly on to sub-saharan Africa. They’ll be back in late February or early March, to breed. They build their nests in large trees or rocky cliffs, and often reuse the same nest year after year. They fix it up and add new materials, so older nests can be 1 to 2 metres in diameter!
Considered Vulnerable in Portugal, the Black Stork is threatened by habitat loss, collision with powerlines, and especially by human activities in its breeding areas, as the species is very sensitive to disturbance. This sensitivity makes it especially important to be extra-careful when watching these birds, to ensure you don’t disturb them, especially near nesting sites.