Lion-tailed macaque (Macaca silenus), a primate endemic to small and severely fragmented rainforests of the Western Ghats in Karnataka, Kerala and Tamil Nadu, continues to be in the ‘endangered’ category in the IUCN Red List of Threatened Species.
The latest conservation status of the primate was updated in the IUCN database recently based on technical reports over the years from a group of researchers including Mewa Singh of the University of Mysore, Ajith Kumar of the Centre for Wildlife Studies, and Honnavalli N. Kumara of the Sálim Ali Centre for Ornithology and Natural History.
As per the technical report, the total wild population of the lion-tailed macaque (LTM) could be about 4,000 individuals consisting of less than 2,500 mature individuals, made up of 47 isolated sub-populations in seven different locations in the three States. The population is expected to suffer an estimated decline of over 20% in the next 25 years due to varied reasons including hunting, roadkills and habitat loss, it said.
Though the conservation status of the LTM had improved from ‘endangered’ in the first assessment in 1990 to ‘vulnerable’ in 1994, its status has remained endangered since 1996.
The researchers have observed that the population of the mostly shy and frugivorous primate, which prefers upper canopies of evergreen rainforests, was registering a declining trend in LTM’s home range in the Western Ghats hill ranges from the Kalakkad Hills in the south to Sirsi-Honnavara in the north at an altitude of 100 to 1,300 metres.
“Fragmentation of the habitat is one of the major threats to the species. Several habitats that remain disconnected from others can be linked. There are contiguous habitats in Karnataka and Kerala. The population in Valparai plateau of the Anamalai Tiger Reserve (ATR) can also be linked to other populations. Enough research has been done on various aspects of the conservation of the primate over the last several years and now it is the responsibility of the authorities to implement them on ground,” says Prof. Mewa Singh. Researchers also feel that continuous monitoring is crucial to understand the population trend for the management and protection of LTMs in their habitat.
Capture and release of bonnet macaque from human habitations to the habitat of LTMs could also affect their health as the former primate can cause the spread of novel parasites that was published in a 2019 paper titled ‘Prevalence of gastrointestinal parasites in lion-tailed macaque Macaca silenus in central Western Ghats, India’ with Shanthala Kumar as the lead author.
The foraging and social interactions of LTMs have seen drastic changes when they live in human modified areas, says researcher Ashni Kumar Dhawale, who observed one of the four LTM groups in Valparai to study its behavioural responses to a matrix of anthropogenic habitats.
“Due to easy access to human-origin food, cooked and uncooked, they spend minimal time for foraging. But the time taken for resting has considerably increased, possibly due to more time consumed for the digestion of human foods. While aggression among males increased in human modified areas, dominance among the female members intensified as food resources occur in a clumped distribution. Low-ranking individuals were found foraging human foods at higher frequencies compared to dominant individuals possibly due to delayed access to food as privileged first access being reserved for dominant members of the troop,” she said.
Officials of ATR are in the preparations to estimate the LTM population of Valparai in October in collaboration with the Nature Conservation Foundation.
