A new species of nightjar ( Caprimulgus ) from Timor and Wetar, Lesser Sunda Islands, Wallacea

The nightjars of the Caprimulgus macrurus complex are distributed from Pakistan to Australia and comprise six morphologically similar but vocally distinct species. Fieldwork on Timor and Wetar, Lesser Sunda Islands, has resulted in the discovery of a seventh species in the complex, which we describe as a new species. This species has previously been confused with Caprimulgus macrurus, Caprimulgus celebensis and Caprimulgus manillensis but it differs from these and all other species in the complex by at least 13 vocal characters. Discriminant function analysis correctly classified all recordings in the complex to species. Caprimulgus ritae is known from five adult museum specimens, which are the smallest in the complex and which differ from other species in the complex in several morphological characters. A molecular phylogenetic analysis indicated that C. ritae is sister to C. meesi from Flores and Sumba, and that these species together are sister to C. macrurus. C. ritae is a tropical forest specialist occurring from sea level to at least 1500 m (probably mostly below 1000 m). Lowland and montane forests on Timor are threatened. Wetar is one of the least developed islands in Indonesia, and retains >95% natural vegetation, dominated by Eucalyptus woodlands, with tropical forests in river gorges and slopes in upland areas. Pressure for development is accelerating throughout the range of C. ritae, and a detailed assessment of its conservation status is urgently needed.