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Data from: Seasonality in daily movement patterns of mandrills revealed by combining direct tracking and camera traps

Citation

Hongo, Shun; Nakashima, Yoshihiro; Akomo-Okoue, Etienne François; Mindonga-Nguelet, Fred Loïque (2022), Data from: Seasonality in daily movement patterns of mandrills revealed by combining direct tracking and camera traps, Dryad, Dataset, https://doi.org/10.5061/dryad.fj6q573td

Abstract

This dataset, containing three CSV files and one R code, was collected in a field study on wild mandrill (Mandrillus sphinx) groups in Moukalaba-Doudou National Park, Gabon. We analysed the data to examine the temporal variations in movement rates of mandrill groups and their seasonal changes.

Summary of Methods and Results

In a 400-km2 rainforest area in Moukalaba-Doudou National Park, Gabon, we tracked unidentified groups 46 times in 2009–2013; in the same area, we systematically placed 157 terrestrial camera traps in 2012–2014 and recorded groups 309 times. Generalised additive mixed models (GAMM) of the tracking data (GPSerror.csvTrackData.csv) indicated that the group travel speed varied with time and season: In the fruiting season, the movement rate fluctuated with time in a bimodal pattern; in the non-fruiting season, it increased monotonously with time. Predicted day ranges were longer in the fruiting season (7.10 km) than in the non-fruiting season (6.18 km). These seasonal differences suggest responses to changes in food resources and temperature. Camera-trap detection rates (CameraData.csv) showed similar temporal and seasonal patterns to the tracking data, allowing us to generalise our findings to the population level. Moreover, cameras never detected mandrills at night, and we observed that they slept high in trees and hardly moved until the next morning, all suggesting their strict avoidance of night-time movement.

Methods

GPSerror.csv (data on the measurement error of a handy GPS device) was collected from a handy GPS device (Garmin GPSmap 62s) left in a particular place in the forested study area. We used a generalised linear model (GLM) to analyse the distribution of the measurement error of GPS coordinates.

TrackData.csv (data on direct tracking of mandrill groups) was collected by the direct tracking of mandrill groups in 2009–2013 using handy GPS devices (Garmin GPSmap 60csx/62s). We used generalised additive mixed models (GAMMs, with the R package "gamm4") to examine the temporal and seasonal changes in movement rates of the groups.

CameraData.csv (data on camera-trap detections of mandrills) was collected in a camera-trap survey in 2012–2014. We used circular kernel density estimation (with the R package "activity") to examine the temporal and seasonal variations in camera-trap detection rates of mandrill groups.

Supplementary_Rcode.R includes all the codes used in the analyses.

Usage Notes

All data is collected by the authors and can be freely cited and used by anyone. The data do not contain any personal data.

--- Descriptions of the data files ---

GPSerror.csv

Column"ID": ID of data points.

Column "Date": The date on which the data point was collected.

Column "Duration": Time interval (in minutes) between this and the next data points.

Column "Coord_x": X-axis of the coordinate in UTM. To mask the exact locations according to the conservation standpoint, the values are transformed by subtracting a certain number.

Column "Coord_y": Y-axis of the coordinate in UTM. To mask the exact locations according to the conservation standpoint, the values are transformed by subtracting a certain number.

Column "Elev": Elevation of the coordinate in metres.

Column "Distance": Distance (in metre) between this and the next data points. (= ((Coord_x)2 + (Coord_y)2 + (Elev)2)1/2)\

TrackData.csv

Column "ID": ID of data points.

Column "Track_session": ID of the direct tracking sessions. A session started when we found a mandrill group; it ended when we left the group. Numbers indicate the date in the order year–month–day. Used as a random smooth effect in GAMMs.

Column "Track_bout": ID of the direct tracking bouts. A bout started when we found a mandrill group or re-found the same group that we had lost earlier on the same day; it ended when we lost the group, or when the group began sleeping at dusk. Therefore, One tracking session can include several tracking bouts. Numbers indicate the date in the order year–month–day. NOTE: we used tracking sessions and NOT tracking bouts as a random smooth effect in the GAMM analysis.

Column "Season": A categorical variable of two levels: fruit indicates the fruiting season (September–February); non.fruit indicates the non-fruiting season (March–August). Used as a parametric fixed effect in GAMMs.

Column "Track_order": Sequential numbers of the data by tracking bout.

Column "Date_time": Date and time at which the data was collected.

Column "Time": Time at which the data was collected (in 24-hour). Used as a smooth fixed effect in GAMMs.

Column "Duration": Time interval (in minutes) between this and the next data points. Used as an offset term in GAMMs.

Column "Coord_x": X-axis of the coordinate in UTM. To mask the exact locations according to the conservation standpoint, the values are transformed by subtracting a certain number.

Column "Coord_y": Y-axis of the coordinate in UTM. To mask the exact locations according to the conservation standpoint, the values are transformed by subtracting a certain number.

Column "Elevation": Elevation of the coordinate in metres.

Column "Distance": Distance (in metre) between this and the next data points (= ((Coord_x)2 + (Coord_y)2 + (Elev)2)1/2) [Used as "the response variable in GAMMs]

Column "Sleep": A categorical variable of two levels: indicates the group was not sleeping at that data point; 1 indicates the group was beginning to sleep at that data point.

CameraData.csv

Column "ID": ID of data points. There are many missing numbers because we used only detections of mandrills.

Column "Folder": Name of folders where videos were included. This collum is not used for analysis.

Column "Transect": ID of transects. This collum is not used for analysis.

Column "Station": ID of camera-trap stations. This collum is not used for analysis.

Column "File": ID of video files. This collum is not used for analysis.

Column "Season": A categorical variable of two levels: fruit indicates the fruiting season (September–February); non.fruit indicates the non-fruiting season (March–August). We analysed the data separately for each season.

Column "Date_time": Date and time of the detection.

Column "Date": Date of the detection.

Column "Hour": Time of the detection (in 24-hour)

Column "Time": Time of the detection (in radian)

Column "Species": Animal species of the detection

Column "Social_org": Social organisation of the detected mandrills: group indicates social groups; sol_male indicates solitary males; male_asso indicates small groups of a few males; unknown indicates that the social organisation was not determined. We used only group detections for the analysis.

Column "Continued_10min": A logical variable. TRUE indicates that this video had been taken less than 10 minutes after the previous mandrill detection. We used only FALSE data for the analysis.

Funding

Japan Society for the Promotion of Science, Award: JSPS KAKENHI JP19107007

Kyoto University, Award: Global COE Program A06

Japan Society for the Promotion of Science, Award: JSPS KAKENHI JP12J01884

JST-JICA/SATREPS, Award: PROCOBHA