The span of Ciconia Nigra can vary from 185 to 200 cm, and its body length from 95 to 100 cm. Its average weight is 3kg. There is no sexual dimorphism: male and female look alike.

The Black Stork differs from the white one in that it is slightly smaller and much darker.

Breeding female storks come back as early as February. Immature 2-year-old fowl join Europe a little later, in May.

Storks use thermal updrafts to travel during migration. In nesting areas, mating partners start their courtship with brief vocalisations (whistling sounds). Chicks squeak for food when an adult comes near, and squawk when disturbed.

Breeding pairs come back from their African wintering areas in late February – early March.

 They usually build their nest in a tall tree. In France, they will mostly go for an oak, or a maritime pine in the Centre region, or a beech. In some countries such as Turkey or Spain, black storks also nest in cliffs.

 The average height for a nest is 12 meters, but it can vary from 7 to 24 meters.

 The nest is made of twigs and its diameter can reach 2 meters. The inside of the nest is covered with moss. The nest is often set on a side branch, near a fork, at the bottom of the crown, far from the trunk.

It is very rare to find a nest in the midst of the crown. In maritime pines, most nests are built in the axis of the trunk, level to a nook or a crooked spot.

The black stork can also use former raptor eyries. An eyrie can be used for many years: 11 years in France, in the Ardennes, and up to 37 years in Latvia. Still, the black stork is more attached to a specific forest area than to a nest in itself. A second nest can usually be found within the next hundred meters or up to 3 or 4 km. A yearly change of nest can be explained by a breeding failure the previous year or by an alteration of the nearby habitat.

The incubation period is 32 days long, and both adults take turns for brooding the eggs. During that period, black storks remain as discreet as possible. Eggs usually hatch from late April to early May (or even early June). Chicks stay in the nest from 63 to 71 days, when they are fed by their parents 4,5 times a day on average.

In 2019, the total breeding population in France is estimated at a maximum of 100 pairs. On average, it is estimated that 3 chicks per brood reach the age when they are able to fly. In more densely-populated countries, the number is lower (1,05 per brood in Estonia in 2002).

The monitoring of a specific breeding pair during the brooding period has shown that adults occupy an 800-km² territory (a 40×20 km rectangle); they can travel a 20-km distance to find food. During wintering, birds dwell in African wadis and move as they become drier. At night, the birds gather in sleeping areas situated in the tall trees of the wooded savannah.