We already have insights about the sophisticated ways many animals species communicate with one another, but researchers were unprepared for what they discovered when studying bat communications. It turns out bats argue and rant–a lot.
Scientists recorded a group of 22 Egyptian fruit bats for 75 days. Then using a modified machine learning algorithm originally designed for recognizing human voices, they fed 15,000 calls into the software. They then analyzed the corresponding video to see if they could match the calls to certain activities.
The results demonstrated that Egyptian fruit bats aren’t just making high pitched squeals when they gather together in their roosts. They are communicating specific problems they are having with one another. In other words, bat noises are not just random as scientists once believed.
The researchers were able to classify 60 percent of the calls into four categories. One of the call types indicates the bats are arguing about food. Another indicates a dispute about their positions within the sleeping cluster. A third call is reserved toward males making unwanted mating advances, and the fourth vocalization type occurs when a bat argues with another bat for sitting too close. In fact, the bats make slightly different versions of the calls when speaking to different individuals within the group, similar to a human using a different tone of voice when talking to different people. (Besides humans, only dolphins and a handful of other species are known to address individuals rather than making broad communication sounds.)
The scientists want to investigate whether bats are born knowing this “language” or if they learn it over time while living in their colonies. They also want to know if the bats use similar communication outside the roost. To uncover the answers, their next study involves attaching microphones to some bats and releasing them into the wild.
The bigger picture: Having decoded the language of fruit bats, it might even be possible to use similar techniques to begin understanding nuanced communications in other species as well.
Journal reference: Prat, Y., Taub, M. & Yovel, Y. Everyday bat vocalizations contain information about emitter, addressee, context, and behavior. Scientific Reports, 6, 39419 (2016). https://doi.org/10.1038/srep39419
Posted by Geriandi