|Madagascar, Comoro Is
The genus Circus is a cosmopolitan genus of about ten species. They are medium-sized, slender hawks, the female being considerably larger than the male. They are characterised by long, narrow, rounded tails, small beaks and long, slender legs. The most notable characteristic is the owl-like ruff of facial feathers that cover unusually large ear openings – an adaptation not for low-light hunting, but to locate prey by their rustling and squeaking in tall grasses.
In Madagascar, this species is likely to have very poor nesting success owing to the regular and comprehensive burning of grasslands and marshes, especially in the central high-plateau region (to produce fresh grazing areas and to clear land), and due to egg-hunting and nest-destruction by local people. Most savannah fires occur from August to November, thus coinciding with the species’s breeding season. For example, in October 2005, all seven nests at Ambohitantely were destroyed by fire during the incubation period, resulting in the loss of all eggs. Conversion of wetlands for rice farming is also likely to have a negative impact upon the species. Over 80% of marshland in Madagascar has been converted into rice fields, mainly in areas of dense human inhabitation. Nestlings are often taken by people for food and interviews with local communities have revealed that adults are also hunted for food. The species is also persecuted because of its threat to poultry, however in one study of breeding birds, domestic chickens accounted for only 1% of prey items. The disturbance of marshes appears to limit the number of breeding pairs present, and human activities during the cultivation period may force the movement of birds. The species requires undisturbed areas with unaltered savannah, however land-use activities have rendered it absent from many areas of Madagascar.