Sonotype‐level responses of Afrotropical hipposiderid bats to local‐scale effects of rainforest structure

Abstract

Bats exhibit a variety of life‐history traits that can serve as valuable surrogate metrics of terrestrial ecosystem health. Here, we investigate how sonotype activity of hipposiderid bats covaries with habitat structure at finer spatial scales. We recorded passive echolocation calls and measured key habitat attributes in six rainforests in the Lomami and Yangambi landscapes, Democratic Republic of the Congo. Using bat passes as a measure of sonotype activity, we clustered echolocation calls based on call structure similarity to control for within‐sonotype variation in activity. Over 432 h of recording, we detected 370 passes matching a hipposiderid sonotype in three subgroups, recovering eight potential species. Open habitats negatively affected sonotype activity in the Hipposideros subgroup, which was associated with higher echolocation frequencies. Indeed, activity peaked in the early evening when mean post‐sunset temperature was above the nocturnal average and declined until early morning when mean temperatures dropped below the nightly average. All habitat variables were marginally correlated with the activity of the Doryrhina subgroup, whereas Macronycteris was more active in open habitats. Our findings indicate a probable flexibility of habitat use in lower echolocating bats and point to three possible foraging guilds that modulate hipposiderid bat responses to habitat structure.

Drivers affecting habitat use in Afrotropical hipposiderid and pteropodid bats

“…The data that support the findings of this study are openly available in the Dryad Digital Repository: https://doi.org/10.5061/ dryad.1ns1r n901 (Mande et al, 2023).…”

“…Since this modeling approach requires a fixed list of possible species (S), we generated a species occurrence matrix containing the "true" observation state at each station. We included previous field data from both Lomami and Yangambi (Gembu et al unpublished data;Mande et al, 2023) in the analyses to control for potential false-negative detections, that is, species may be present but unrecorded (Miller et al, 2011). Species observed at least once were assigned an encounter history of 1, otherwise 0 for unobserved but previously recorded, to control for false-positive errors in the estimates.…”