Gleaning insectivorous bats eat seasonably in a West African rice farming landscape: implications for ecosystem services

Abstract

Insectivorous bats are key predators of arthropods, yet their ecological roles in African agroecosystems remain underexplored. This study investigates the dietary variation of two slit-faced bats (Nycteris cf. hispida and Nycteris thebaica/gambiensis) inhabiting a rural landscape in Guinea-Bissau, West Africa. Understanding the feeding patterns of these bats is essential for assessing their contribution to natural pest control and biodiversity conservation. Using DNA metabarcoding and next-generation sequencing, we examined spatial and temporal variations in prey consumption to assess dietary overlap, flexibility and potential pest suppression. Specifically, we focused on the following objectives: a) to assess whether the diet composition of N. cf. hispida varies spatially (between roosts) and temporally; b) to characterise how the diet of the two Nycteris species varies throughout the sampling period and to compare these patterns; c) to evaluate whether both predators track seasonal changes in prey, particularly potential agricultural pests. We analysed 166 faecal samples that revealed 488 distinct OTUs. Nycteris cf. hispida exhibited pronounced temporal variation in its diet, likely reflecting changes in arthropod occurrence, while N. thebaica/gambiensis showed less pronounced seasonal shifts. Despite shared roosts, differences in prey composition and foraging strategies suggest partial niche differentiation, with N. cf. hispida favouring ground-dwelling invertebrates and N. thebaica/gambiensis exploiting more aerial arthropods. Both bats consumed potential agricultural pests, including Spodoptera littoralis, Macrotermes bellicosus and Orseolia oryzae. These results highlight the dynamic foraging response of Nycteris bats to changes in prey availability and their potential role in controlling insect pests in West African rice systems. This study contributes to a growing body of evidence supporting insectivorous bats' ecological and economic value and underscores the importance of conserving bat populations in rural landscapes.