Social communication in the lesser long-nosed bat, Leptonycteris yerbabuenae

The ability of bats to use the echoes of their emitted acoustic signals to navigate and find food in complete darkness has been studied in detail for many decades. In recent years, the study of their use of sound for social communication has received increasing attention in bioacoustics research (Fenton 2003). Although the chiropteran order comprises over 1,300 species, only a very small percentage have had their social call repertoire and its usage thoroughly investigated (Smotherman et al. 2016; Bohn & Gillam 2018; Chaverri et al. 2018). This is particularly true for the New World family of leaf-nosed bats (Phyllostomidae), where the vast majority of studies on acoustic communication comes from just a handful of species (primarily from Carollia perspicillata, Phyllostomus hastatus and P. discolor).

Phyllostomid bats inhabit a range of habitats from the southern parts of North America to the northern parts of South America. With more than 150 species in at least 49 genera, it is the second largest bat family (Datzmann et al. 2010). This taxon shows a remarkable diversity in several aspects of their ecology, for example in mating systems (Adams et al. 2018) and feeding specializations (Datzmann et al. 2010).

For my Ph.D. thesis, I work with a colony of Leptonycteris yerbabuenae, a medium-sized Phyllostomid and one of three species of the genus. It mainly feeds on floral resources, e.g. nectar and pollen of flowers from columnar cacti and agaves (Cole & Wilson 2006), many of which are exclusively pollinated by it (Fleming & Holland 2018). To detect and localize flowers, it integrates two sensory channels using acoustic and scent cues from flowers (Gonzalez-Terrazas et al. 2016). Additionally, it is an outstanding long-distance traveller, both on nightly foraging flights (Medellín et al. 2018) and during an annual migration from Mexico to the southern USA to form maternity colonies (Rojas-Martínez et al. 1999).

In my work, I want to study their vocal communication behaviour in different behavioural contexts. Therefore, I plan to combine recordings from the captive colony in the laboratory with on-board recordings from wild bats. I am particularly interested in the following questions: [1] Are certain vocalization types associated with specific behaviours? [2] Are there sex-specific differences in the usage of the social call repertoire? [3] Which acoustic features can be used to distinguish between individual bats? [4] What call types are used during different echolocation tasks and do they use calls that might serve a dual function – echolocation and social communication?

[02] Walter MH, Schnitzler H-U (2017) Spectral call features provide information about the aggression level of greater mouse-eared bats (Myotis myotis) during agonistic interactions. Bioacoustics (in press). DOI:10.1080/09524622.2017.1359798

[01] Stanley CQ, Walter MH, Venkatraman MX, Wilkinson GS (2016) Insect noise avoidance in the dawn chorus of Neotropical birds. Animal Behaviour 112: 255-265. DOI:10.1016/j.anbehav.2015.12.003