Temporal variation in fruit-feeding forest butterfly communities in Sabah, Borneo.

Abstract

This study investigated temporal variation in fruit-feeding butterfly communities in Sabah, Borneo. Fruit-baited traps were used to sample butterflies in primary forest and
forest that had been selectively logged 11-12 years previously in 1988 and 1989. Traps were hung 1-2m from the ground along four transects in primary and logged forest (8
km in total). Traps were operated for 12 days each month for a year (October 1999 to September 2000). This study focused on Nymphalid species whose adults feed on rotting fruit. A total of 3996 individuals from 63 species were recorded during the study. Rates of species accumulation were slightly higher in logged forest than in primary forest, but there was no difference between habitats in species diversity over the whole year. However, whereas diversity was generally higher in primary forest during
March-July, it was higher in logged forest during August-February, resulting in a significant habitat by time-of-year interaction for two separate diversity indices. β diversity (species turnover) also showed opposite differences between habitats at different times of year. These results have important implications for the reliability of short-term studies that do not sample over the course of an entire year. Effects of three environmental factors (sunshine, rainfall and fruit availability) on butterfly diversity were investigated. Rainfall had a significant positive effect on species evenness (Simpson's index) and abundance of P. franck. Rainfall may have acted via its effects on adult survival as well as via indirect effects on larval host plant quality.