One of the five groups of lion-tailed macaques in Puthuthottam, located in private plantations near the city of Valparai, had 117 individuals. | Photo credit: SPECIAL ARAGEMENT
Long-term monitoring of the endangered lion macaque (LTM) in the Valparai Plateau has found that the shy rainforest primate forms unusually large groups in unprotected areas, a recently published study says.
One of the five LTM groups at Puthuthottam, located in private plantations near the city of Valparai, had 117 individuals, while the average primate group size in protected areas in the Western Ghats is less than 20. The other group at Puthuthottam had 51 LTMs. Another population on a private estate in Korangumudi had 78 individuals.
Puthuthottam, Pannimedu, Korangumudi and Tata Coffee were private plantations (unprotected areas) that were among the 10 fragmented areas surveyed for the study. Up to 34 individuals recorded in a group at Panathiar-1 was the highest among groups in protected areas surveyed by the study: Differential Demographic Responses of Lion-tailed Macaques to Habitat Fragmentation: Four Decades of Population Monitoring in Anamalai Hills, Western Ghats and Perspectives for Management and Conservation.
The total LTM population in the Valparai Plateau, which falls under the Anamalai Tiger Reserve (ATR), was estimated to be around 800 in 37 groups, according to a study that was conducted between February 2021 and August 2024. Of the 37 groups recorded in 10 rainforest fragments, five were in Puthutni Tatuttam Coffee.mu and one The remaining 29 groups were recorded in fragments within protected areas like Varagaliyar Complex, Iyerpadi – Akkamalai Complex, Andiparai Shola, Hindustan Shola, Sankaranakudi Shola and Waterfall Shola.
According to long-term monitoring data, a single group of 17 individuals was recorded at Puthuthottam in 1984, which split into two groups of 40 individuals by 1994. These two groups remained until 2010 with 122 individuals before splitting into four groups in 2015. The population size increased to almost 200 to 2225 individuals by 2015. The 19 LTMs recorded in Korangumudi in 1990 increased to 83 by 2021. Although the groups in TATA Coffee and Pannimedu remained around 15 and seven respectively for several decades, both groups showed an increase in group size to 21 and 15 by 2024.
According to Honnavalli N. Kumara, principal scientist at the Salim Ali Center for Ornithology and Natural History and one of the authors of the study, the LTM population has been relatively stable in all protected areas, while steady growth has been observed in private fragments such as Puthuthottam and Korangumudi.
“Now one group from Puthuthottam visits Valparai town and another group spends a lot of time in Rottikadai. People are also seen feeding LTMs in places like Iyerpadi. If they are not approached by LTMs, they get used to this type of feeding and may move more into human-populated areas, affecting their behavior and population dynamics,” he warns.
Although the factors behind the exponential population growth in Puthuthottam remain unknown, according to the study co-authored by Santanu Mahato, G. Umapathy, Mridula Singh and Mewa Singh, human food consumption, availability of cultivated fruits and adaptation to human presence and provisioning may be among the reasons.
Published – 18 Feb 2026 21:38 IST