The Gray slender loris is a strange-looking primate, with large, round eyes and long thin limbs. Despite the name, it is not always gray, some of them being quite reddish, and each subspecies (of which there are four) varies in coat color. It is a tree-dwelling animal that travels along the branches on all fours, stretching between the ends of branches to reach the next tree. Like all lorises, each of its digits has a nail, except for the second one of each foot, which has instead a relatively long claw, the ‘toilet’ claw, which it uses when grooming. The loris’s canines and lower incisors are also used for grooming.
The Gray slender loris inhabits eastern and southern India and Sri Lanka. Inside this large range, every subspecies lives in a different area. The Mysore slender loris occurs in the Eastern Ghats, in eastern and southern India, while the Malabar slender loris inhabits the Western Ghats and the west coast of India. The remaining two subspecies, the dry zone slender loris and the highland slender loris, both live in Sri Lanka, in the north central dry areas and the central province respectively. Gray slender lorises inhabit forest, plantations, and jungles of dry shrub, and seem to prefer degraded forests instead of primary forest, often living in areas near human habitations.
Gray slender lorises are nocturnal animals and live a social life. In the daytime, they nearly always sleep in groups of 2 to 7 that usually consist of a female adult, her offspring, and a few adult or sub-adult males. These sleeping groups usually use the same places and consist of the same members. The site is generally in the centre of the primary female’s home range. Individuals who sleep together usually form themselves into a “sleeping ball” in which they tangle their limbs together. They wake at dusk and groom each other, with grooming taking place between individuals of either gender and all ages. Gray slender lorises usually hunt on their own, though friendly foraging pairs have been recorded. Social interactions generally occur between male and female adults, as well as between adults and juveniles, but they are hardly ever between same gender adults.
Gray slender lorises are insectivores, eating mostly ants and termites, though they will also eat beetles and orthopterans, mollusks, spiders, and occasionally small vertebrates.
Gray slender lorises practice a polygynandrous (promiscuous) system of mating. Female lorises mate with multiple males during one mating season and may mate with multiple males one after the other. Throughout the year males will mate with multiple females. According to some researchers, the mating season takes place biannually, from April to June and then October to December, while others claim that births are occur throughout the year and reproductive peaks are just the result of the gestation period being for 5.5 months. Equal amounts of single and twin births occur. The timeline for infant development is typically shaped by ‘parking’ of infants by their mothers. During the first 4 weeks, mothers carry their infants all the time, then they begin to ‘park’ them near the sleeping area at night before going off to forage. Mothers provide milk that is unusually high-energy before weaning, which takes place at 5 months old. Males reach sexual maturity at about 10 months, and females between 10 and 15 months.
Throughout its range, many human activities threaten the gray slender loris. In India and Sri Lanka, habitat loss has affected this species, and the plantations where the loris lives are an unstable habitat, subject to harvesting at any time. The Gray slender loris is also a victim of road traffic, can be electrocuted on power lines that are un-insulated, and hunted for the pet trade and to be used for traditional medicines.
The IUCN Red List and other sources do not provide the Gray slender loris total population size. Currently this species is classified as Least Concern (LC), but its numbers today are decreasing.
Gray slender lorises affect insect populations as predators, especially termites and ants, as these creatures make up most of their diet.