Personality affects dynamics of an experimental pathogen in little brown bats

Social vocalizations indicate behavioural type in Glossophagine bats

Vocalizations play a crucial role in the social systems of many animals and may inadvertently reveal behavioural characteristics of the sender. Bats, the second largest mammalian order, rely extensively on vocalizations owing to their nocturnal lifestyle and complex social systems, making them ideal for studying links between vocalizations and consistent behavioural traits. In this study, we developed a new testing regime to investigate whether consistent individual vocalization differences in nectarivorous bats are associated with specific behavioural types. We exposed 60 wild, male Glossophaga soricina handleyi bats to novel and risky stressors and assessed their behavioural and vocal responses. Proactive, exploratory and bold bats were more likely to produce social calls, and among the vocalizing bats, more agitated bats produced higher numbers of social calls. We thus show that bat vocalization behaviour can be indicative of a certain behavioural type, potentially allowing conspecifics to assess personalities from a distance, which in turn could impact subsequent social interactions, group dynamics and reproductive success. Our results, in combination with previous findings in birds, suggest that advertent or inadvertent long-distance broadcasting of personality may be widespread, thus opening up new exciting questions about the links between vocalizations and sociality.

Context-specific variation and repeatability in behavioral traits of bent-wing bats

Animals may show consistent among-individual behavioral differences over time and in different contexts, and these tendencies may be correlated to one another and emerge as behavioral syndromes. The cross-context variation in these behavioral tendencies, however, is rarely explored with animals in contexts associated with different locomotion modes. This study assessed the variation and repeatability in behavioral traits of bent-wing bats Miniopterus fuliginosus in southern Taiwan, and the effects of contextual settings associated with locomotion mode. The bats were sampled in the dry winter season, and their behaviors were measured in hole-board box (HB) and tunnel box (TB) tests, both suited for quadrupedal movements of the bats, and flight-tent (FT) tests that allowed for flying behaviors. The bats in the FT tests showed more interindividual and between-trial behavioral variation than those in the HB and TB tests. Nearly all of the behaviors in the TB and FT tests, but only half of those in the HB tests, showed medium to high repeatability. These repeatable behaviors were grouped into distinct behavioral traits of boldness, activity, and exploration, which were correlated to one another across contexts. In addition, we observed a consistently higher correlation between behavioral categories across the HB and TB contexts than between either of these contexts and the FT context. The results indicate consistent among-individual behavioral differences across time and contexts in wildly caught bent-wing bats. The findings of behavioral repeatability and cross-context correlations also indicate context-dependent variation and suggest that test devices which allow for flight behaviors, such as flight tents or cages, may provide a more suitable setting for measuring the behaviors and animal personalities of bats, particularly for those species that display less or little quadrupedal movements.