Bat droppings collection by ants in epigean environments

Abstract

Ants can be found in insect communities associated with droppings, but most studies about this interaction have been carried out in subterranean environments, specifically in the study of the interaction between ants and bat guano. In this report, we describe the first case of interaction between seven different ant species and the droppings of two bat species in epigean environments. The study was performed in bat roosts monitored from March to October 2022 in the Doñana Biological Reserve of the Doñana National Park (Huelva, SW Spain). It was carried out via direct observations of droppings deposited on the ground surface or in tree-mounted dropping collectors below bat boxes. We report a total of 37 interactions by seven different species of ants with droppings of two species of bat, the soprano pipistrelle (Pipistrellus pygmaeus) and the greater noctule (Nyctalus lasiopterus), in four different habitats (Eucalyptus camaldulensis, Pinus pinea, Populus alba and ground surface). The generalist characters and the omnivorous diets of the ant species observed, in addition to the abundant availability of droppings during a period of food scarcity, suggest that droppings are transported as a food resource, with the consequent implications that this interaction may have on faecal degradation and nutrient cycling, as one of the supporting services provided by ants.