Butterfly ecology in the Arabuko Sokoke forest

Sinaida Hesse, master student of Technical University Munich, conducted a detailed butterfly assessment along line-transects during a two month stay (April-June 2016) in the Arabuko Sokoke forest, incorporating different forest types (Cynometra, Brachystegia, mixed forest), and forest qualities – the core vs edge of the forest, different types of plantations, agroforestry systems. Based on these data she will identify different species communities depending the vegetation type, and the effect from negative edge effects (habitat quality). Butterflies and butterfly farming provides an important alternative income source for the local people (see the Kipepepo project, see pictures below), but also arise many questions about potential negative impact from the illeagal collection of butterflies (and their pupae) after the market of butterfly trading were established. This study will be repeated during spring 2017 by using identical transects.

Sina found that butterfly species richness and species composition strongly vary among forest types (Brachystegia forest, Cynometra forest and mixed forest), and strongly declines towards the forest border (negative edge effect) and in tree plantations. Apart from the number of species, also species composition changed considerably. While forest specialists occur restricted to Brachystegia and Cynometra forest, as well as mixed forest, the butterfly communities are dominated by habitat generalists in low quality habitat structures, like the forest boarder or tree plantations. Repeated data collection will be conducted along the same line transects in 2017, to complete and finalize this data-set.