This species breeds on islands in the Mediterranean. It is a long-distance migrant, wintering in Africa. It is rare north of its breeding range. It nests colonially on coastal cliffs, laying up to four eggs.
It is an elegant bird of prey, like a large Hobby or a small slender Peregrine Falcon, with its long pointed wings, long tail and slim body. There are two colour phases. The adult dark morph is all dark brown, with black underwing coverts. The light morph is more like a juvenile Hobby, but has buff underparts, and also shows the contrast between the black underwing coverts and paler base to the flight feathers.
Young birds are also like a large juvenile Hobby, but the pale underparts contrast with darker wingtips and wing coverts.
It will take large insects, such as dragonflies, which are transferred from talons to beak and eaten in flight. However, this species has a delayed breeding season, in late summer, because it is a specialist hunter of migrating birds which pass through the Mediterranean islands at this time of year. It captures small birds in flight, using its speed and aerobatic skills.
Birds spend much time cruising along coastal cliffs with steady wingbeats watching for tired incoming migrants.
The call is a typical falcon kek-kek-kek.
This bird is named after Eleonora of Arborea, national heroine of Sardinia.