From forest to farmland: butterfly diversity and habitat associations along a gradient of forest conversion in Southwestern Cameroon K. Serge Bobo 1,2, *, Matthias Waltert 1 , Heleen Fermon 1 , John Njokagbor 3 and Michael Mu¨hlenberg 1 1 Centre for Nature Conservation (Dept 1), Georg-August University, Von-Siebold-Straße 2, 37075 Go ¨ttingen, Germany; 2 Ministry of Wildlife and Forestry, Yaounde, Cameroon; 3 Korup National Park, P.O. Box 36, Mundemba, Southwest Cameroon; *Author for correspondence (e-mail: bobokadiri@yahoo.fr; phone: +49- 551-399-220; fax: +49-551-399-234) Received 22 February 2005; accepted in revised form 9 June 2005 Key words: Biodiversity conservation, Cameroon, Fruit-feeding butterflies, Land use systems, Tropical rainforest Abstract Worldwide, tropical landscapes are increasingly dominated by human land use systems and natural forest cover is decreasing rapidly. We studied frugivorous butterflies and several vegetation parameters in 24 sampling stations distributed over near-primary forest (NF), secondary forest (SF), agroforestry and annual culture sites in the Northeastern part of the Korup region, SW Cameroon. As in other studies, both butterfly species richness and abundance were significantly affected by habitat modification. Butterfly richness and abundance were highest in SF and agroforestry sites and significantly lower in NF and annual crop sites. Butterfly species richness increased significantly with increasing tree density, but seemed to decrease with increasing herb diversity and density in annual crop farms. A significant negative correlation was found between butterfly geographic range and their preference for NF sites. Our results also showed that agroforestry systems, containing remnants of natural forest, can help to sustain high site richness, but appear to have low complementarity through loss of endemic species confined to more undisturbed hab- itats. Our study also indicated that the abundance of selected restricted-range butterflies, particularly in the family Nymphalidae, appears to be a good indicator to assess and monitor forest disturbance. Introduction Protecting pristine forests is irrefutably the most effective conservation strategy (Schulze et al. 2004b) but protected areas comprise only 8% of tropical forests (Rice et al. 2001) and their extension is almost impossible nowadays (Schulze et al. 2004b), while degradation is still ongoing due to many encroachments. Anthropogenic habitats are largely unknown in terms of their contribution to biodiversity conservation (Schulze et al. 2004b; Waltert et al. 2004). They may be important in terms of preserving at least a fraction of tropical biodiversity (Hughes et al. 2002; Waltert et al. 2005) of which insects are a major part, but few data are available (Holloway et al. 1992; Eggleton et al. 1995; Lawton et al. 1998). Butterfly diversity in natural and disturbed forests has been studied before in Southeast Asia (Spitzer et al. 1993; Hill et al. 1995; Beck et Schulze 2000; Schulze et al. 2004a,b; Fermon et al. 2005), in the Neotropics (Lovejoy et al. 1986; Brown 1991; Sparrow et al. 1994; DeVries et al. 1997; Wood and Gillman 1998), in Madagascar (Kremen 1992) Journal of Insect Conservation (2006) 10: 29–42 Ó Springer 2006 DOI 10.1007/s10841-005-8564-x