Original Research Article Folia Primatol 2016;87:291–302 DOI: 10.1159/000452405 Distribution of the Grey Slender Loris ( Loris lyddekerianus Cabrera, 1908) in Tamil Nadu, Southern India Honnavalli N. Kumara   a R. Sasi   b, c Subash Chandran   c Sindhu Radhakrishna   c a  Sálim Ali Centre for Ornithology and Natural History, Coimbatore, b  Department of Anthropology, University of Madras, Chennai, and c  School of Natural Sciences and Engineering, National Institute of Advanced Studies, Bangalore, India Keywords Slender loris · Occurrence · Relative abundance · Eastern Ghats · Conservation · Lorisidae · Strepsirrhini Abstract The grey slender loris Loris lydekkerianus, one of only two nocturnal primates of In- dia, is found in the southern part of the country. Our understanding of its geographical distribution is largely based on historical records and short surveys, and little is known of its occurrence in southern India today. We sought to establish the relative abundance of this species in 26 districts in the state of Tamil Nadu and the union territory of Pondi- cherry in southern India. We sighted lorises in 19 districts, and their relative abundance ranged from 0.01 to 2.21/km. The south-central districts of Tamil Nadu showed the high- est densities of lorises, while the western districts showed the lowest. Based on these results, we recommend increased protection measures for the forest patches of the East- ern Ghats mountains in order to ensure the long-term survival of the grey slender loris. © 2016 S. Karger AG, Basel Introduction The grey slender loris Loris lydekkerianus is a nocturnal primate endemic to southern India and central and north central Sri Lanka [Groves, 2001; Brandon-Jones et al., 2004]. Two subspecies occur in India: the Mysore slender loris Loris lydekke- rianus lydekkerianus is said to inhabit the Eastern Ghats mountain range, while the Received: May 7, 2015 Accepted after revision: October 11, 2016 Published online: November 29, 2016 Sindhu Radhakrishna National Institute of Advanced Studies Indian Institute of Science Campus Bangalore 560012 (India) E-Mail sindhu  @  nias.iisc.ernet.in © 2016 S. Karger AG, Basel 0015–5713/16/0875–0291$39.50/0 www.karger.com/fpr E-Mail karger@karger.com Downloaded by: Verlag S. KARGER AG, BASEL 172.16.7.51 - 1/19/2017 10:13:10 AM