Fruit bats: social foraging behavior – Prof. Ran Nathan’s Movement Ecology Lab

Fruit bats: social foraging behavior – Prof. Ran Nathan’s Movement Ecology Lab

The Egyptian fruit bat is an important seed dispersal vector for a variety of plants, including invasive species.  It is also known to be a highly social species, but exact foraging patterns and social associations remain a mystery. With the help of high-resolution location tracking applied to almost an entire bat colony and graph theory to unravel the social network, researchers hope to gain insights into these mysterious behaviors.


Understanding the environmental and social drivers of resource choice using high-resolution location tracking of the Egyptian Fruit bat.


What we did

We have captured >60 bats and tagged them with ATLAS location-tracking devices which enables localization of individuals every 4 seconds. Thanks to this high-resolution data we were able to identify almost every tree the bats fed on and the movements they made between them throughout the year. In order to understand the mechanisms behind tree choice, we summarized this large dataset (>1m data points) into individual-based spatial networks that connect trees (nodes) via individual bat movements (links). We are testing network metrics, such as tree-centrality and individual-bat movement structure against fruit availability and spread to see why bats move the way they do. In later stages, we will also investigate whether particular movement patterns, such as exploratory behaviors, are correlated with a specific social statuses of bats in a corresponding social network (spatial overlap between dyads).


To this end, we found that bats show high fidelity to very specific trees, which serve as central "hubs". Preliminary results suggest that tree choice is most likely attributed to social motivations rather than the spatial array of food resources.