Satellite remote sensing of habitat suitability for ungulates and ostrich in the Kalahari of Botswana

Abstract

Past studies have suggested that knowledge about the condition, spatial distribution and temporal development of the vegetation cover and grass greenness in the semi-arid Kalahari could be of great value in understanding wild herbivore movements. This study explored the possibility of using NOAA–AVHRR GAC NDVI imagery to monitor vegetation condition in the southern Kalahari. Grass greenness estimates from ground surveys and aerial surveys were used to test the validity of the satellite imagery. Ground truthing suggested significant correlations with grass greenness estimates and NDVI in a portion of the Kalahari previously identified as the wildlife core area of the southern and central Kalahari. The results suggest that density distributions of some species were related to habitat greenness and the satellite imagery could be used to test habitat suitability for wildebeest, hartebeest and ostrich on a regional scale in the Kalahari. Results improved when livestock areas were excluded from the analysis, possibly because bush encroachment obscured the lower NDVI values expected as a result of heavy grazing.