The Link between Seba Fruit bats and Stalactites

The motivation of this project was to create a more enriching space in the Denver Zoo temporary enclosures for the Seba short-tailed fruit bat (Carollia perspicillata). Previous research suggests C. perspicillata tends to roost in caves that contain naturally formed stalactites. Stalactites are often present in bat caves and provide  structures for roosting. Carollia perspicillata roost in large clusters  of over 1,000 individuals, therefore, living with other bats is essential for this species. Our goal was to investigate whether adding environmental complexity changed the clustering behavior of the C. perspicillata within their temporary enclosure, which originally lacked environmental complexity. We predicted that if environmental complexity provides bats with more choices of where to roost, then bats may disperse more and congregate in smaller clusters. We manipulated environmental complexity by adding 3-D printed stalactites to the ceilings of the  temporary enclosures. This study was based on observational research that used video cameras to record C. perspicillata clustering behavior throughout the night and day. Our results show that cluster sized decreased following the addition of stalactites during the day, but this difference was absent at night. Furthermore, video footage and anecdotal observations confirm that the bats huddle between stalactites and hang from these structures. Additional research is needed to determine whether changes in cluster size are associated with physiological variables, such as eustress or distress.