It was formerly regarded as a subspecies of the Réunion harrier (C. maillardi) but is increasingly treated as a separate species.

It is thought to be declining as a result of hunting and habitat destruction and is classed as endangered by BirdLife International.

It feeds mainly on birds such as the Madagascar partridge and also takes reptiles, amphibians, rodents and insects.

It typically feeds by flying low over the ground and dropping down rapidly when it spots its prey.

It breeds in marshland, building a nest of grass and stems on the ground or low in a bush.