Data from: Elephant space use and habitat selection change across drought timescales
Data files
May 20, 2026 version files 375.86 MB
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elephant_data.zip
375.85 MB
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README.md
3.92 KB
Abstract
Droughts are globally increasing in duration, frequency and intensity, thereby endangering the survival of wildlife species. Understanding how animals behave during drought is essential to develop conservation measures that aid wildlife survival and prevent human-wildlife conflict in a changing climate. Yet, little is known about animal behavior during drought. Specifically, existing work on animal behavior and drought typically does not account for the timescale and the intensity of the drought. We use 19 years of GPS data from the African elephant (Loxodonta africana), a species at risk from drought, collected in Southern Africa, where droughts are increasingly common. We study if there is a connection (i) between drought and the amount of space elephants use, and (ii) between drought and elephant habitat selection. We examine drought conditions using the Standardized Precipitation-Evapotranspiration Index (SPEI) at a 1-month, a 3-month, and a 12-month timescale. We found that elephants had smaller home ranges and movement distances when their environment became drier at a 1-month timescale. Importantly, SPEI at a 1-month timescale was a better predictor of elephant home range size than precipitation and NDVI, suggesting that drought conditions may affect elephant movement through more ways than a lack of precipitation or vegetation greenness. In addition, we found that elephant habitat selection changed as a function of drought conditions at all three timescales, but the direction of the change often depended on the timescale of the drought. We found that elephants were closer to inland water and in areas with lower human population density during drought at a 1-month timescale, but farther from inland water and in areas with higher human population density when drought lasted longer. Overall, our results show that drought conditions, as measured by SPEI, predict elephant movement behavior. We stress the importance of (i) using a drought index rather than only precipitation levels to examine drought conditions, and (ii) considering the timescale at which drought occurs. These insights could help to better understand how animals behave during drought and to assess the risk of human-wildlife conflict across species, regions, and drought timescales.
Dataset DOI: 10.5061/dryad.5mkkwh7m4
Description of the data and file structure
This dataset contains the data needed to perform the analysis described in:
Bouwman, I., Claassen, T., Chase, M.J., Landen, K., Huijbregts, M.A.J., Tucker, M.A. Elephant space use and habitat selection change across drought timescales. Journal of Animal Ecology
Data include (i) 1,025 elephant monthly home ranges and movement distances annotated with environmental covariates in the monthly home ranges; and (ii) environmental covariates for GPS locations that elephants visited during each month as well as for locations randomly sampled from the elephant monthly home range. Analyses showed that the Standardized Precipitation-Evapotranspiration Index (SPEI) at a 1-month timescale was a predictor of elephant monthly home range size and movement distance, and that elephant habitat selection changed across SPEI timescales.
Questions can be directed to Irene Bouwman (irene.bouwman@ru.nl)
File: elephant_data.zip
File structure:
The elephant_data folder contains the following files:
elephant_home_ranges.csv
elephant_habitat_selection.csv
File description:
elephant_home_ranges.csv
This file contains the monthly home ranges and movement distances of 57 elephants and a total of 1,025 individual-year-month combinations.
Column names:
ID: The identifier of the individual elephant.
yearMonth: The year and month for which the home range was calculated.
monthlyHomeRange_km2: The monthly home range of the individual in squared kilometres, calculated as the 95% Minimum Convex Polygon (MCP).
sumMonthlyDisplacement_km: The total displacement of the individual during the month in kilometres.
temperature: The mean of the maximum daily temperature in the individual's monthly home range during the month in °C.
SPEI01: The mean Standardized Precipitation-Evapotranspiration Index (SPEI) in the monthly home range at a 1-month timescale.
SPEI03: The mean Standardized Precipitation-Evapotranspiration Index (SPEI) in the monthly home range at a 3-month timescale.
SPEI12: The mean Standardized Precipitation-Evapotranspiration Index (SPEI) in the monthly home range at a 12-month timescale.
precipitation: The monthly cumulative precipitation in the monthly home range in mm.
NDVI: The monthly mean Normalized Difference Vegetation Index (NDVI) in the monthly home range.
HII: The mean Human Impact Index (HII) in the monthly home range.
elephant_habitat_selection.csv
This file contains environmental covariates at visited locations of 57 elephants as well as locations randomly sampled from the monthly home ranges of each individual.
Column names:
ID: The identifier of the individual elephant.
yearMonth: The year and month in which the locations were visited and for which random locations were sampled from the home range.
distanceToWater_km: The distance from the location to the nearest inland water source in kilometres.
distanceToWaterhole_m: The distance from the location to the nearest artificial waterhole in metres.
monthlyCumPrecipitation: The cumulative monthly precipitation at the location in mm.
monthlyMeanNDVI: The monthly mean of the Normalized Difference Vegetation Index (NDVI) at the location.
slope: The slope at the location in degrees.
treeCover: The percentage of tree cover at the location.
cropOrNot: A binary variable indicating whether the location is in a cropland (1) or not (0).
populationDensity: The human population density at the location as number of people per 300 m raster cell.
usedOrAvailable: A binary variable indicating whether the location was visited by the elephant during the month (1) or randomly sampled from the individual's monthly home range (0).
