An open source web GIS tool for analysis and visualization of elephant GPS telemetry data, alongside environmental and anthropogenic variables

Abstract: The movement and distribution of ecologically important herbivores such as elephants are of great significance to conservation biologist seeking to understand the fundamental triggers that influence their mobility and the extent to which these parameters affect how they utilize their immediate and surrounding resources. The recent advancement in animal tracking technology coupled with the availability of moderate to high-resolution satellite data, permits scientists to develop elephant cognitive maps of their adjacent environment, thus offering novel opportunities for research in the fields of wildlife movement ecology and the wider conservation biology. This research study explored the use of an interactive web GIS application in mapping and visualization of elephant GPS telemetry data alongside other critical variables such a weather, environmental and anthropogenic factors - that are known to have a direct impact in determining presence/absence of elephants in a particular location. The web GIS approach allows for the automated processing, analysis, and visualization of Earth Observation data and the integration of the Elephant GPS Telemetry data, thus, permitting the end user to access, query, and visualize the time series datasets in a simple and intuitive graphical user interface. This web GIS tool leveraged on the existing applications and modules such as: MODIS Reprojection Toolkit, ArcPy, and Python for automated preprocessing of the Earth Observation data; ArcGIS desktop and Movement Ecology Tool for developing customized elephant movement ecology products; PostgreSQL-PostGIS as the database server; Geoserver as the web GIS server and a host of other open source libraries such as HTML, ExtJS, GeoExt, OpenLayers and Python-CGI in the development of the web GIS application. From the web GIS tool, we deduced that NDVI was the main biophysical factor that influenced the immediate movement and distribution of elephant, in comparison to other factors such as temperature and rainfall. The fragmented nature of ecosystem compounded with a high level of encroachment to protected areas also limited free movement of elephant within their home ranges. Female elephant spent more time in protected areas compared to their male counterpart in spite of their periodically visits’ to high risk zones at some point in time, most likely in search of vital elements such as salt or clay licks. All the three elephants had their home ranges extending through low elevated areas. There was also evidence of close association between these elephants as a result of their overlapping home ranges and close proximities at various stages such as during the male perennial hyperactivity (musth) episodes which coincided with the wet period. All the three elephants also had their core ranges closely overlapping with the existing riparian zones.