Distribution and community composition of carabid beetles (Coleoptera: Carabidae) in Ranomafana National Park, Madagascar

Abstract

Forest loss has caused fragmentation and destruction of habitats, and thereby presents serious extinction risk to many endemic species in Madagascar. Among many other arthropod groups, carabid beetles are poorly known in Madagascar as regards their distribution, habitat requirements and taxonomy. The aim of this study is to document community composition, distribution patterns and habitat preferences of carabids in the forest-dominated Ranomafana National Park, south-eastern Madagascar. Carabids were collected by hand and trunk traps from secondary forest, primary forest and nearby village areas. In total, 4314 individuals representing 125 species, including 38 new species, were collected. Almost 70% of the species were recorded in very low abundances. Furthermore, there were only a few species in intermediate abundance classes, while the three most abundant species represented ≈ 36% of the total catch. The carabid community seems to be very species rich, consisting mostly of species in low abundances. A positive correlation was found between abundance and occupancy despite high variation among species distribution patterns. Small population sizes of endemic species with nearby habitat destruction make the species especially vulnerable to extinction and increase the importance of protecting Ranomafana National Park.