Climate Change Projections of Current and Future Distributions of the Endemic Loris lydekkerianus (Lorinae) in Peninsular India

Abstract

Loris lydekkerianus (L. lydekkerianus) are endemic primates of peninsular India. The current and future potential distribution and range shift of L. lydekkerianus were studied using a maximum entropy (maxent) machine learning algorithm. Four scenarios of the Intergovernmental Panel on Climate Change (IPCC)’s fifth assessment, that is, representative concentration pathway (RCP) 4.5 and RCP 8.5 for the years 2050 and 2070, were examined using observed ecological variables and known data of species occurrence, obtained from both published literature and field surveys. This supplied 200 species occurrence points. Spatial thinning was applied to reduce dataset biases. The preliminary extraction of species occurrence data using quantum geographic information system (QGIS 2.14) generated a residual value of <0.001 reflecting reliable extraction. This ecological model suggests an expansion of potentially suitable habitat of Loris lydekkerianus malabaricus in the central Western Ghats (WG) and shrinking of the habitat of Loris lydekkerianus lydekkerianus in the Eastern Ghats (EG). A third unnamed, undescribed subspecies of Loris lydekkerianus found during this investigation was more vulnerable to climate change. Field-collected datasets confirm that Loris lydekkerianus malabaricus prefer wetter habitats of the WG, whereas Loris lydekkerianus lydekkerianus were more common in the dry, rain-shadow areas of the WG and the Deccan plateau, extending into the EG and coastal areas of Tamil Nadu. The unnamed subspecies of L. lydekkerianus (hereafter L. lydekkerianus, ssp. A) prefers an intermediate climatic area, that is, neither the wet parts of the WG nor the dry parts. Ecological models on the future potential distribution of Loris lydekkerianus lydekkerianus predict positive expansion of the habitat for RCP 4.5 for 2050 and 2070, whereas the RCP 8.5 (2050) and RCP 8.5 (2070) scenarios predict high impacts on the habitat due to climate change. Range shift models predict a considerable shift in the present habitat range and expansion for Loris lydekkerianus malabaricus and Loris lydekkerianus lydekkerianus, respectively, and no expansion for the L. lydekkerianus ssp. A for 2050 and 2070. We also predict that suitable habitat areas of L. lydekkerianus ssp. A will shrink by 99%. Therefore, L. lydekkerianus ssp. A stands highly vulnerable to the changing climate of peninsular India.