Distribution of the Grey Slender Loris (Loris lyddekerianus Cabrera, 1908) in Tamil Nadu, Southern India

Abstract

The grey slender loris Loris lydekkerianus, one of only two nocturnal primates of India, 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 Pondicherry 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 highest 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 Eastern Ghats mountains in order to ensure the long-term survival of the grey slender loris.

Coexistence between Javan Slow Lorises (Nycticebus javanicus) and Humans in a Dynamic Agroforestry Landscape in West Java, Indonesia

“…Researchers have recorded the pollination of agricultural plants by nocturnal primates (Javan slow lorises Nycticebus javanicus in Java, greater slow loris N. coucang in Malaysia) (Nekaris 2014;Wiens et al 2006). Insect consumption, which is also likely to include agricultural pests, has been observed in agroecosystems among Javan slow loris in Java (Rode-Margono et al 2015), Mysore slender loris (Loris lydekkerianus lydekkerianus) in India (Nekaris and Rasmussen 2003;Kumara et al 2016), Milne-Edward's potto (Perodicticus edwardsi) in Cameroon (Pimley et al 2006), and by Dian's tarsier (Tarsius dianae) in Sulawesi (Merker et al 2005).…”

A review of research on the distribution, ecology, behaviour, and conservation of the Slender Loris Loris lydekkerianus (Mammalia: Primates: Lorisidae) in India

“…More extensive spatial surveys were carried out spanning a distance of 734 km covering several forest divisions in southern Andhra Pradesh (Singh et J TT al. 2000), 1,041 km, including 703 km in a jeep and 31 km walk, in northern and central Kerala (Radhakrishna et al 2011), 641 km in a jeep in southern Kerala (Sasi & Kumara 2014), 557.1 km by walk and 844.6 km in a jeep in Tamil Nadu (Kumara et al 2016), and almost the entire state of Karnataka (Kumara et al 2006). In all the studies mentioned above, the encounter rate as loris/km represented abundance.…”

“…In the mid-1990s, the primate research team from the University of Mysore initiated systematic field surveys. Since then, Slender Lorises have been surveyed in selected regions of Dindigul (Singh et al 1999), southern Andhra Pradesh (Singh et al 2000), large areas of Karnataka (Kumara et al 2006), northern and central Kerala (Radhakrishna et al 2011), Tumkur and Bangalore forest divisions (Das et al 2011), southern Kerala (Sasi & Kumara 2014), large areas of Tamil Nadu (Kumara et al 2016), and Aralam Wildlife Sanctuary (Gnanaolivu et al 2020). The actual surveys carried out so far have reported the extent of the distribution of the Malabar Slender Loris from the southern tip of the Western Ghats up to 15.8 ⁰N in the Belgavi district of Karnataka, the subspecies occurring primarily in the wet forests on the western slopes of the Ghats.…”

“…Within habitat, lorises appear in places with more tree density and canopy contiguity and less branch lopping and human disturbance (Kar Gupta 1998). Surveyed in large areas of Tamil Nadu (Kumara et al 2016), the relative abundance of lorises varied from 0.01 /km to 2.21 /km in different regions. Most of the loris populations are found in southcentral districts.…”

Sleep patterns, daytime predation, and the evolution of diurnal sleep site selection in lorisiforms

“…two additional species of Perodicticus , four Nycticebus , one Galagoides , and one Sciurocheirus ). Fourth, researchers studying nocturnal primates have amassed substantial new field data from countries such as Angola, Cameroon, Equatorial Guinea, The Gambia, Kenya, Malawi, South Africa, Tanzania, Cambodia, India, Indonesia, Sri Lanka, and Vietnam (Bersacola, Svensson, & Bearder, ; Butynski & De Jong, ; Butynski, De Jong, Perkin, Bearder, & Honess, ; De Jong & Butynski, ; Engelbrecht, ; Génin et al, ; Kappeler et al, ; Kenyon et al, ; Kumara, Sasi, Chandran, & Radhakrishna, ; Nekaris, ,b, 2014; Nekaris & Jayewardene, ; Pimley, Bearder, & Dixson, ,b; Ray, Wren, & Bowers, ; Svensson & Bearder, ). Fifth, primatologists working on diurnal primates have taken an interest in certain lorisiforms, as lorisiforms share sleep sites with diurnal primates (Llorente, Sabater, & Houle, ), or are hunted by them (Boesch & Boesch, ; Hardus et al, ; Nishida, Uehara, & Nyundo, ; O'Malley, ; Pruetz & Bertolani, ).…”