The slender lorises are a genus of loris native to India and Sri Lanka. The genus comprises two species, the red slender loris found in Sri Lanka and the gray slender loris from Sri Lanka and India. Slender lorises spend most of their life in trees, traveling along the tops of branches with slow and precise movements. They are found in tropical rainforests, scrub forests, semi-deciduous forests, and swamps. The primates have lifespans of approximately 15 years and are nocturnal. Slender lorises generally feed on insects, reptiles, plant shoots, and fruit.
The red slender loris is found in Sri Lanka while the gray slender loris is found in Sri Lanka and India. The two subspecies of red slender loris differ in their habitat preference, the lowland loris, L. t. tardigradus, favors wet lowland forests (up to 470 m above sea level) south western wet-zone of Sri Lanka while the mountain loris, L. t. nycticeboides, prefers cloud, montane, and highland evergreen forests at elevations of 1800–2300 m. The gray slender loris can be found in tropical rainforests, primary and some secondary, coastal acacia scrub forests, semi-evergreen forests, swamps, and bamboo groves up to 2000 m above sea level.