Human Land-Use and Forest Regeneration as Drivers of Bat Diversity and Activity in a Tropical Dry Forest

Abstract

Tropical dry forests are one of the most under-protected ecosystems, yet many important ecosystem services are provided by these forests. The Área de Conservación Guanacaste (ACG) in Costa Rica is the largest forest restoration project in the world, undertaken largely by preventing fires. Chiroptera is a highly dynamic order that comprises half of the mammals in Costa Rica (113 bat species) and provide many of important services, including: pollination, seed dispersal, and pest control. However, how these species respond to forest regeneration is still not well understood. To study the effect of the moon and forest age on bat activity and diversity, bats were surveyed by way of mist netting and acoustic recording for approximately five nights in four different forest growth treatments: early, intermediate, old, and plantation. My study found that bat activity decreased when the moon was fuller. Surveys of old growth treatments show that they have the highest species richness, closely followed by plantation treatments. Similarly, the older the forest treatment, the more foraging guilds it was found to support. Certain generalist seed dispersers persisted in all treatments while other, rarer bats were found only in old forest treatments. This has significant implications for conservation, demonstrating that promoting forest regeneration is an effective way of restoring ecosystem services to forests, though while some species may be unaffected by the age of the forest, others are more sensitive and may take more time or possibly never return to their previous habitats. Further studies should be undertaken to understand exactly which forest segments can be utilized by humans and which must be protected to preserve biodiversity and ecosystem functioning.