Wintering habitat modelling for conservation of Eurasian vultures in northern India

Abstract

Eurasian Black Vulture (EBV) and Eurasian Griffon Vulture (EGV), while residents elsewhere, winter in Uttar Pradesh, India. Knowledge of the habitat and regulating factors is obligatory for protection and better management of these vultures. Therefore, different types of habitats were mapped using eight species distribution models. Presence records from field survey, published data and citizen science, and 23 bioenvironmental raster layers were the model inputs. Eighteen models were developed whose strength varied greatly. As per the performance indicators, GBM and GLM were found to be superior models for EGV. For EBV all models were acceptable. MARS, with good model strength, was rejected on the grounds of field verification. However, the Ensemble model, overall, was found the best. As per this model, good habitat was restricted mostly in the Tarai ecozone. The top two vital variables were NDVI, and bio13 for both the vultures. The most vital temperature variable for EGV was bio08 while bio09 for EBV. Tarai ecozone showed the largest expanse of suitable area for both the vultures followed by Vindhyan-Bundelkhand, Gangetic plains and Semi-arid ecozones. Among the two, EBV (49000 km2) had more suitable area than EGV (37000 km2). Agricultural areas were found to be largely unsuitable. As per land cover, good habitat was mostly confined in forests. For better management of these wintering vultures which need only roosting and foraging, it is proposed that destruction of forested habitat and decrease in foraging materials needed immediate attention and control.