Habitat preference and functional traits influence responses of tropical butterflies to varied habitat disturbance

Biodiversity is declining worldwide due to anthropogenic disturbances. There is a vital need to be able to predict the impacts of these disturbances on ecological communities. Species’ attributes such as habitat preference and functional morphological traits may help in uncovering broad patterns in their responses to anthropogenic habitat disturbance. We examined trait-habitat associations in 251 tropical butterfly species by measuring three morphological traits (body mass, wing length and proboscis length) and classifying species according to their habitat preference (forest, ecotone, open). We then correlated these measures (morphological traits and habitat preference) to responses of butterflies to two common habitat disturbances, i.e., a road passing through forest, and dominance of an invasive plant Lantana camara. Both evolutionary relatedness (i.e., family affiliation) and habitat preference explained considerable variation in butterfly morphological traits, suggesting a relationship between evolutionary relatedness, habitat preference and morphology. Both habitat preference and morphological traits influenced response to habitat disturbance: (a) forest roads were frequented by smaller butterflies (b) Lantana-dominated patches were depauperate in larger butterfly species and species with long probosces that are usually associated with deep-flowered forest plants, and (c) habitat preference was related to disturbance from both road and Lantana, with forest-specialized butterfly species showing a negative response. These results suggest that tropical butterflies show generalized responses to habitat disturbance according to their habitat preference and functional morphological traits.