Rodriguez-Herrera, B. | bioRxiv Science

bioRxiv2021

Social behaviour and vocalizations of the tent-roosting Honduran White Bat

Bats are highly gregarious animals, displaying a large spectrum of social systems with different organizational structures. One important factor shaping sociality is group stability. To maintain group cohesion and stability, bats often rely on social vocal communication. The Honduran white bat, Ectophylla alba exhibits an unusual social structure compared to other tent-roosting species. This small white-furred bat lives in perennial stable mixed-sex groups. Tent construction requires several individuals and, as the only tent roosting species so far, involves both sexes. The bats social system and ecology render this species an interesting candidate to study social behaviour and social vocal communication. In our study, we investigated the social behaviour and vocalizations of E. alba in the tent by observing two stable groups, including pups, in the wild. We documented 16 different behaviours, among others, play and fur chewing, a behaviour presumably used for scent-marking. Moreover, we found 10 distinct social call types in addition to echolocation calls, and, for seven call types, we were able to identify the corresponding behavioural context. Most of the social call types were affiliative, including two types of contact calls, maternal directives, pup isolation calls and a call type related to the fur-chewing behaviour. In sum, this study entails an ethogram and describes the first vocal repertoire of a tent-roosting phyllostomid bat, providing the basis for further in-depth studies about the sociality and vocal communication in E. alba.

animal behavior and cognition↗

bioRxiv2018

Two dispersers are better than one: a ‘bird-fig’ attracts bats via nocturnal scent

The plant genus Ficus is a keystone resource in tropical ecoystems. One of the unique features of figs is the diversity of fruit traits, which in many cases match their various dispersers, the so-called fruit syndromes. The classic example of this is the strong phenotypic differences found between figs with bat and bird dispersers (color, size, and presentation). The bird-fig Ficus colubrinae represents an exception to this trend since it attracts the small frugivorous bat species Ectophylla alba at night, but during the day attracts bird visitors. Here we investigate the mechanism by which this bird-fig attracts bats despite its fruit traits, which should appeal solely to birds. We performed feeding experiments with Ectophylla alba to assess the role of fruit scent in the detection of ripe fruits. Ectophylla alba was capable of finding ripe figs by scent alone under exclusion of other sensory cues. This suggests that scent is the main foraging cue for Ectophylla alba. Analyses of odor bouquets from the bat- and bird-dispersal phases (i.e. day and night) differed significantly in their composition of volatiles. The combination of these two findings raises the question whether E. alba and F. colubrinae resemble a co-adaptation that enables a phenotypically classic bird-fig to attract bat dispersers by an olfactory signal at night thus maximizing dispersal.

ecology↗