Consistent long-distance foraging flights across years and seasons at colony level in a Neotropical bat

All foraging animals face a trade-off: how much time should they invest in exploitation of known resources versus exploration to discover new resources? For group-living central place foragers, this balance is challenging. Due to the nature of their movement patterns, exploration and exploitation are often mutually exclusive, while the availability of social information may discourage individuals from exploring. To examine these trade-offs, we GPS-tracked groups of greater spear-nosed bats (Phyllostomus hastatus) from three colonies on Isla Colón, Panamá. During the dry season, when these omnivores forage on the nectar of unpredictable balsa flowers, bats consistently travelled long distances to remote, colony-specific foraging areas, bypassing flowering trees closer to their roosts. They continued using these areas in the wet season, when feeding on a diverse, presumably ubiquitous diet, but also visited other, similarly distant foraging areas. Foraging areas were shared within, but not always between colonies. Our longitudinal dataset suggests that bats from each colony invest in long-distance commutes to socially learned shared foraging areas, bypassing other available food patches. Rather than exploring nearby resources, these bats exploit colony specific foraging locations that appear to be culturally transmitted. These results give insight into how social animals might diverge from optimal foraging.

Methods
The data set used in this analysis was collected at three different colonies of Phyllostomus hastatus, in Isla Colón, Bocas del Toro, Panamá during the years 2016 -2023. Bats were captured inside caves, over roost cavities, using a ring trap. Bats were processed and biologgers were attached to their backs using skin glue. The biologgers lasted for 1-14 days.

The GPS data retrieved from the GPS devices are stored in the Movebank repository.

GPS data can be found in the following links:

2016 data: O’Mara, MT, Dechmann, DKN. 2023. Data from: Greater spear nosed bats commute long distances alone, rest together, but forage apart.  Movebank Data Repository. https://doi.org/10.5441/001/1.282

2021-2022 data: Calderón-Capote MC, van Toor ML, O'Mara MT,  Bayer TD, Crofoot MC, Dechmann DKN. [Year]. Data from: Consistent long-distance foraging flights across years and seasons at colony level in a Neotropical bat [2021-2022]. Movebank Data Repository. https://doi.org/10.5441/001/1.321

2023 data: Bayer TD, Barría LM, Gómez LF, Lee JP, Aguilar G, O’Mara MT. 2024. Data from: Consistent long-distance foraging flights across years and seasons at colony level in a Neotropical bat [2023]. Movebank Data Repository. https://doi.org/10.5441/001/1.322

The GPS data also includes associated reference data from the bats available at Movebank Data Repository (same links provided).

The GPS data was analyzed following the code workflow files in this reposirory using the R version 4.3.3 (2024-02-29). R files are commented accordingly to ensure the reproducibility of the analysis.