DOI: 10.5061/dryad.51c59zwgp
title: Tracks for Egyptian fruit bats included in the field manipulation for testing the use of the communal roost as an information center hypothesis

description: According to the Information Centre Hypothesis (ICH), colonial species use
 social information in roosts to locate ephemeral resources. Validating the
 ICH necessitates showing that uninformed individuals follow informed ones
 to the new resource. However, this following behavior may not be essential
 when individuals memorize the resources’ locations. For instance, Egyptian
 fruit bats forage on spatially predictable trees, but some bear fruit at
 unpredictable times. These circumstances suggest an alternative ICH
 pathway in which bats learn when fruits emerge from social cues in the
 roost but then use spatial memory to locate them without following
 conspecifics. Here, using a unique field manipulation and high-frequency
 tracking data, we test for this alternative pathway: We introduced bats
 smeared with the fruit odor of the unpredictably fruiting Ficus sycomorus
 trees to the roost, when they bore no fruits, and then tracked the
 movement of conspecifics exposed to the manipulated social cue. As
 predicted, bats visited the F. sycomorus trees with significantly higher
 probabilities than during routine foraging trips (of &gt;200 bats).
 Our results show how the integration of spatial memory and social cues
 leads to efficient resource tracking and highlight the value of using
 large movement datasets and field experiments in behavioral ecology.
description: Movement tracks of Egyptian fruit bats (<em>Rousettus
 aegyptiacus</em>) that were exposed to a manipulation introducing an
 odor cue of a newly emerging fruit (<em>Ficus
 sycomorus</em>),<em> </em>by releasing bats smeared with
 fruit pulp into the cave-roost. The tracks were collected using the ATLAS
 reverse-GPS system (see Nathan et al. 2022, Toledo et al. 2020), in the
 Hula Valley, Israel. The provided tracks underwent basic filtering for
 localization errors (see Gupte et al. 2022, Lourie et al. 2021) but were
 not segmented to separate commutes.
description: # Tracks for Egyptian fruit bats included in the field manipulation for
 testing the use of the communal roost as an information center hypothesis
 Movement tracks derived from the ATLAS reverse-GPS system for Egyptian
 fruit bats (*Rousettus aegyptiacus*) in the Hula Valley, Israel. ##
 Description of the data The tracks are of bats exposed to a manipulation
 in which some (n=14) were introduced to the communal cave-roost smeared
 with the fruit pulp of a *Ficus sycomorus* tree during the time the only
 two trees in the landscape bore no fruits. The reminder bats (n=57) were
 tracked but not manipulated with the fruit odors. Importantly, *F.
 sycomorus* is characterized by having unpredictable fruiting regimens in
 this region, which supports the hypothesis that the bats will use social
 information (the odor cue, shared publicly) to know when the fruits ripen
 but then navigate to the trees' locations owing to their advanced
 spatial memory capabilities, without following conspecifics (see Toledo et
 al. 2020). The tracks provided here are meant to enable visualization of
 the movement of bats in the field manipulation and see that they visit the
 two target trees (location of the trees provided as well). Tracks are
 divided into the three manipulation campaigns (different dates) and saved
 as SQLite files. ### Definition of variables in the file
 "manipulations\_trees\_locations.csv" Locations of *Ficus
 sycomorus* trees that the tracked bats are expected to visit following the
 manipulation: **X_ITM**: X-coordinate of the location of *Ficus sycomorus*
 trees in the Israel Transverse Mercator (ITM) coordinate system (meters)
 **Y_ITM**: Y-coordinate of the location of *Ficus sycomorus* trees in the
 Israel Transverse Mercator (ITM) (meters) **Lat_WGS84**: Latitude of the
 trees in the World Geodetic System 1984 (WGS84) coordinate system
 **Long_WGS84**: Longitude of the trees in the World Geodetic System 1984
 (WGS84) coordinate system ### Definition of variables in the bat tracks
 (.sqlite files) **TAG**: Unique identifier to each tracked bat **TIME**:
 Timestamp in Unix time format **X**: X-coordinate of the bat's
 location in the Israel Transverse Mercator (ITM) coordinate system
 (meters) **Y**: Y-coordinate of the bat's location in the Israel
 Transverse Mercator (ITM) coordinate system (meters) **FREQ**: Temporal
 sampling frequency (secs) **NBS**: Number of ATLAS base stations that
 received a radio signal from the bat at each recorded location (min 3 are
 required for trilateration) **VARX**: Variance of the localization signal
 along the X-axis, part of the covariance matrix for location accuracy
 **VARY**: Variance of the localization signal along the Y-axis, part of
 the covariance matrix for location accuracy **COVXY**: Covariance between
 the X and Y localization signals, indicating the degree to which the two
 variables vary together **dateTime**: Combined date and time for each
 recorded location formatted as YYYY-MM-DD HH:MM:SS. **date**: Date for
 each recorded location, formatted as YYYY-MM-DD. **date_global**:
 Represents the "night" period from 3 PM on the recorded date to
 5 AM the following day (relevant for nocturnal activity) **Night**:
 Identifier for unique nights tracked **distance**: Distance traveled
 between consecutive recorded locations of the bat (meters) **dT**: Time
 interval between consecutive locations **spd**: Speed of the bat between
 consecutive locations (distance/dT) **stdVarXY**: Standard deviation of
 the location variance (derived from the covariance matrix), used to filter
 out localizations with poor accuracy. **Lon**: Longitude of the bat's
 location in the World Geodetic System 1984 (WGS84) coordinate system
 **Lat**: Latitude of the bat's location in the World Geodetic System
 1984 (WGS84) coordinate system ### Definition of variables in the file
 "Tags\_manipulated\_and\_visiting.csv" The summary of the
 movement behaviors of the manipulated bats.  **tag**: Unique identifier to
 each bat that visited the focal tree of the manipulation (hence,
 visited="yes") **When?**: date of visiting the tree **Cave
 origin:** Roost of the tag. The manipulations were conducted in Zemer and
 Gershom **date_manipulation:** Date of the manipulation for this tagged
 bat **Nights_after_manipulation:** The number of nights between the
 manipulation and the bats' visit **n_trees_before_same night:** The
 number of trees visited before visiting the focal tree during the night it
 visited it **n_trees_before_all_nights:** The number of trees visited
 before visiting the focal tree during all nights between the manipulation
 and the date of visit **n_trees_after_night:** The number of trees visited
 after visiting the focal tree during the same night
 **Explored_more_that_night:** Assessment based on visualizing the tracks
 to determine whether the tag was particularly explorative during the night
 of visiting the focal tree ### Description of MP4 movies and
 "Description\_table\_movies.xslx" The MP4 files show a
 subset of the tags included in the manipulation for information transfer
 in roosts. For visual clarity, these include all bats that visited the
 focal trees and a representative sample of bats that did not. Each bat has
 a different color, but the colors are not bat-specific across movies. We
 show only dates when one or more bats visited one of the focal trees.
 Tagged bats did not visit the trees during the nights in between. In each
 movie, the two main roost locations are marked with a triangle, and the
 location of the two *Ficus sycomorus* trees of the manipulation is in a
 red circle. Note that due to the relative size of the trees compared to
 the landscape scale, some tags appear to visit the southern tree but were
 visiting nearby it when looking closely. For more details, please map the
 raw tracks used for the movies and the *Ficus* trees’ locations, which are
 also supplied here. For details on the specific tags included in the
 movie, please see the “description_table_movies” Excel file. All movies
 were animated using the MoveVis library in R, with a CARTO basemap
 (Schwalb-Willmann, J.; Remelgado, R.; Safi, K.; Wegmann, M. (2020).
 moveVis: Animating movement trajectories in synchronicity with static or
 temporally dynamic environmental data in R. Methods Ecol Evol. 2020; 11:
 664–669. https://doi.org/10.1111/2041-210X.13374. Variables of the Excel
 file with the tags that were included in each movie: **movie_file:** name
 of the file, with the date. **date_manipulation:** The date when the
 manipulated bats were introduced to the caves (not the date of the movie)
 **tags_visited:** The ID of the tags that visited the trees of the
 manipulation **experiment_category:** Cateogy of bats - either manipulated
 (smeared with the odor of the *F. sycomorus* fruits), or naive (tracked in
 advance, but not smeared).  **date_visiting:** the dates the specific bat
 visited any of the manipulation trees **which_tree?:** Either northern or
 southern trees (marked with a red circle) **cave origin:** Which cave did
 the bat roost in, either Zemer a bit to the North or Gershom below Zemer
 (both marked as a black triangle) **night_visiting_after_manipulation:**
 The night the focal bat visited the trees after the manipulation started
 **tag_color_movie:** The color of the animated bat in each movie ##
 Sharing/Access information The main analyses and data of the manuscript
 can also be found on Zenodo and GitHub (see related links).