Mammal persistence and abundance in tropical rainforest remnants in the southern Western Ghats, India

Occurrence and abundance of mammals were compared in five large protected rainforest patches inside the Indira Gandhi Wildlife Sanctuary and in four smaller, unprotected rainforest fragments in a plantation matrix in the Anamalai hills, southern Western Ghats using line transect distance sampling. Among the 28 mammal species found in contiguous protected rainforests, 24 persisted in unprotected fragments. For most species, population densities were similar between the two strata. Density of arboreal mammal species showed varying habitat correlates across the sites sampled; Indian giant squirrel density was negatively correlated to canopy overlap, lion-tailed macaque density negatively and Nilgiri langur positively to rainforest tree density respectively. Persistence of most mammals on private lands in a fragmented landscape may be attributed to proximity to the surrounding large tract of reserved forest areas as well as recent conservation efforts, including reduction of hunting and protection of fragments. Comparison with past estimates suggests that arboreal mammals have persisted and increased in abundance over the last decade, particularly in private fragments, possibly due to multiple factors, including the ability of the species to use matrix habitats, low hunting pressure, lack of predators and higher food availability.