Breeding Ecology of the Endemic Hook-billed Vanga, Vanga curvirostris, in Madagascar

Abstract

The breeding ecology of the Hook-billed Vanga Vanga curvirostris, which is endemic to Madagascar, was studied on the Masoala Peninsula, northeast Madagascar in October 1999, and in the Ankarafantsika Strict Nature Reserve from October 2000 to January 2001. Five nests discovered during our study were all located 3-10m above the ground in the forks of trees ranging from 390-1260mm in diameter at breast height. Two adults (perhaps a heterosexual pair) participated equally in nest construction, incubation, and care of the young at each nest, and no helpers were observed. Incubation lasted between 22 and 24 days. The nestling period was 20 to 22 days, and the parents delivered invertebrates and small vertebrates, including mainly geckos and chameleons, to nestlings. External morphometric measurements of specimens suggest that the Hook-billed Vanga lacks sexual dimorphism in body size. Less-marked sexual dimorphism, biparental care, and similar sex roles show the Hook-billed Vanga to have a monogamous mating system.