Understanding the relationship between environmental energy availability and bird species richness in Kenya using remote sensing and ancillary data

Abstract

The energy hypothesis predicts that, in regions of roughly equal area, energy flux per unit of area should be the prime determinant of species richness. In the case of plants, primary production represents realized energy capture. Potential evapotranspiration is a measure of community energy use and it is related to terrestrial primary productivity. The best correlate of the latter on regional scale is the Advanced Very High Resolution Radiometer (AVHRR) derived Normalized Difference Vegetation Index (NDVI). I examined the relationship between bird species richness and measures of available environmental energy (interannual maximum average NDVI and mean annual potential evapotranspiration) at a quarter degree scale (55 x 55 km). Statistical analyses revealed higher interannual maximum average NDVI results in higher bird species richness, whereas mean annual potential evapotranspiration correlated negatively with species richness. Understanding these relationships can help in estimating changes in bird species richness in response to global climatic change.