Conservation value of secondary forest habitats to endemic frugivorous butterflies at Mount Kanlaon, Negros Occidental, Philippines

Abstract

Throughout Southeast Asia, removal of old growth forests coincides with rapid expansion of secondary forest landcover. Increasing evidence suggests that secondary forests can contribute to conservation of forest species. The effects of deforestation and subsequent reforestation by secondary vegetation on forest biotas vary geographically, and local data are needed to understand the potential role such forests may play in conservation. In the Philippine Archipelago, a globally distinct biota is coupled with severe deforestation. Focusing solely on old growth forest preservation may no longer be a feasible strategy of achieving conservation goals on islands that have lost the majority of old growth tracts. The potential of Philippine secondary forests to provide habitat for the endemic component of animal communities is not well known. We studied frugivorous butterflies, a common indicator taxon, at a limited spatial scale in Mount Kanlaon Natural Park, Negros Occidental, Philippines. We compared the butterfly communities of three contiguous forest types across a small spatial scale: disturbed secondary forest, regenerating secondary forest, and old growth forest. Hierarchical cluster analysis and NMDS ordination indicated high similarity between communities, though the close proximity of sampling areas may have influenced this similarity. Significant differences between secondary and old growth sites were detected by permutational MANOVA. Endemic butterfly species were abundant in both secondary forest types, and some endemic species were significantly more abundant in secondary forests compared to old growth. These results indicate endemic frugivorous butterflies utilize regenerating habitats at close proximity to intact forest, and provide evidence that secondary forests in the Philippines can contribute to the conservation of endemic components of butterfly communities. However, further study is needed to fully characterize the contribution of regenerating forests, broadly, to conservation strategies in the Philippines.