Foraging behaviour and niche differentiation in two South Asian bee species

Abstract

Pollination across the tropics, including in South Asia, is dominated by social bees. I investigated the behaviour of two species: Apis cerana (Eastern honeybee) and Tetragonula iridipennis (Indian stingless bee) which co-exist in the same environment. The behaviour of these pollinators is somewhat understudied, and this work aims to fill some of the gaps in our knowledge Given the differences in size, colony organisation, and recruitment strategies, I hypothesised that there may be niche partitioning, perhaps mediated by spatial or temporal distribution. I analysed pollen from both species to assess their use of plant resources and found that the two species used different sources, and this is context-dependent. I performed an artificial feeder experiment to investigate the foraging distance of each species. The results indicate that A.cerana has a longer foraging range than T. iridipennis and may be a more efficient forager. Finally, I recorded the daily activity patterns of both species, which show similarities in general foraging activity. However, the results also show that the species may have different temporal patterns with regard to pollen foraging. Temperature also influences activity and pollen foraging in A. cerana but not in T. iridipennis. These behavioural differences may be mediating niche differentiation between the two species.