Rainfall as a significant contributing factor to butterfly seasonality along a climatic gradient in the neotropics

Abstract

AbstractWe analyzed the dynamics of multi-species butterfly communities along a climatic gradient with varying precipitation regimes for three consecutive years, and determine how climatic variables associate with observed butterfly seasonality. To provide a baseline for future studies of how climate change might affect these butterfly populations, we additionally explored the role of butterfly seasonality as a potential contributing factor for their susceptibility to climate variation. As far as we know, this represents the first study that simultaneously sampled and described seasonality patterns of tropical butterfly communities across ecosystems with varying climatic seasonality. A 3-year survey was carried out at three sites (i.e., wet, transition and dry forests) across a climatic gradient in western Ecuador. Butterflies were sampled using traps baited with rotting banana and prawn every two months from Nov 2010 to Sep 2013. Traps were set up at two heights, in the understory and canopy. In total, 7046 individuals of 212 species were sampled over 180 sampling days.Butterfly communities exhibited conspicuous intra and inter-annual variation in temporal dynamics with certain elements (e.g., maximum abundance recorded) of seasonality patterns likely synchronized in seasonal forests (i.e., transition and dry forest) across years but not in aseasonal forests (i.e., wet forest). In addition, the highest numbers of species and individuals occurred during the wet season across all study sites and years; indeed, rainfall was significantly positively associated with temporal abundance. Likewise, butterfly species displaying stronger seasonality were significantly associated with higher rainfall periods in seasonal forests. Variation in precipitation regimes might significantly affect more seasonal species.