Ecological monitoring and indicator taxa: butterfly communities in heterogeneous landscapes of the Western Ghats and Malabar coast, India

As the pace of socioeconomic developments continues to accelerate, the environmental degradation and biodiversity loss become the norm. While it is crucial to constantly monitor and assess ecological impacts, baseline data are scanty for ecologically sensitive regions and biodiversity hotspots such as the Western Ghats. With their great public appeal and ease to work with, butterflies are excellent communities to monitor the ecological health. To characterize the baseline patterns of butterfly communities, using time-constrained counts, we surveyed eight heterogeneous landscapes of the coastal plains of the Western Ghats. We recorded 43,118 individuals and 175 species, with large differences in their diversity and species-specific abundances among habitats. The coastal and semi-evergreen-forest habitats were at the two extremes with intermediate patterns in agricultural and other habitats that suffered diverse anthropogenic pressures. Using indicator value analysis, 22 habitat-specific and several shared indicator species were identified. Even some of the most abundant species showed distinct niches, and therefore can be used as indicator species to monitor community dynamics. Patterns of numerous habitat-specific host-plant butterfly species pairs that were identified were discussed in relation to butterfly abundance and conservation. Implications for insect conservation This study has implications for insect conservation by providing important baseline data on butterfly taxa for future monitoring and assessment of this ecologically sensitive region.