A recent assessment for IUCN reports 3000-3500 of these animals live scattered over several areas in Tamil Nadu, Kerala, Karnataka. The spread of agriculture and tea, coffee, teak and cinchona, construction of water reservoirs for irrigation and power generation, as well as human settlements to support such activities has extremely limited the range of the lion-tailed macaques.
Unlike other macaques the wanderoo avoid any contact with humans of human culture, therefore the destruction of their natural habitat along with human expansion has led to the drastic decrease of their population.
Today in the zoos in various countries there are about 570 of them. But will this be enough and how long will it take to restore the population of the lion-tailed macaques?
Their typical lifestyle is arboreal with the diet consisting mainly of indigenous fruits, leaves, buds, insects and small vertebrates in virgin forest. However, it can also adapt to rapid environmental change and broaden its food choices to include fruits, seeds, shoots, pith, flowers, cones, mesocarp, and other parts of many nonindigenous and pioneer plants. In the forests of Kerala, they were observed preying on nestling and eggs of pigeons.
The wanderoo are quite creative. For example, they have learned how to peel a fruit completely covered in long sharp spines. Before they can collect it, they twist the fruit until the pedicel can be easily torn. To peel off the skin of the fruit, slightly resembling the fruit of a Chestnut, the lion-tailed macaques scale the spines along their growth not to get hurt.
The outstanding characteristic of this species is the silver-white mane, which grows on both males and females. This is how these monkeys got their German name Bartaffe - "beard ape". The other name “the Lion-Tailed Macaque” they received due to a certain trait more pronounces in males - a black tuft at the end of the tail that is similar to a lion's tail.
They live in hierarchical groups of usually 10 to 20 members. Being territorial animals, they defend their area with loud cries, chasing away the invaders and rarely engaging in fights. The life expectancy in the wild is approximately 20 years, while in captivity is up to 30 years.