Lepidoptera diversity, floristic composition and structure of three kaya forests on the south coast of Kenya

Abstract

Three isolated lowland coastal forest patches in Kwale District, namely Kaya Muhaka, Kaya Kinondo and Kaya Diani are classified here as “Wetter mixed semi-deciduous forest”, “Groundwater forest on coral rag” and “Maritime scrub forest”. Although they are sacred to the Digo people, different rates of disturbance were assessed. Kaya Kinondo, which represents a rare forest type along the Kenya coast, is undisturbed at least since the authors began their studies in 1994. Floristic diversity and endemism are high in all Kayas. Lepidoptera diversity is low in Kaya Kinondo, showing that an undisturbed forest does not automatically have a rich Lepidoptera fauna and that the latter does not always respond to a diverse flora. With 352 species, Lepidoptera diversity and endemism is high in Kaya Muhaka. This includes species with a western and central Africa distribution, as well as the Kenyan endemic montane subspecies Charaxes acuminatus shimbanus. Larger moths that appear to be endemic to coastal eastern Africa are presented and others have been preliminary classified as rare for coastal Kenya including species first recorded from Kenya. Two biogeographical groups of coastal forests were found among ca. 30% of the Kenyan butterfly fauna and the authors believe that a further sub-division of the “Usambara-Kwale local centre of endemism” is possible between coastal forests further inland (e.g. Kaya Muhaka) and those close to the shoreline of the Indian Ocean (e.g. Kaya Kinondo, Kaya Diani).

Journal of East African Natural History Vol. 94(1) 2005: 121-163