November 30 is designated the Remembrance Day for Lost Species. I think I will use this time to refresh my memories of Phayre’s leaf monkey (Trachypithecus Phayrei, also called the spectacled langur). We saw a family group of six or seven (this included a juvenile) in Sipahijala wildlife sanctuary, sitting on a tree, munching away at leaves. At first we thought they were the familiar rhesus monkey, but when we looked at them we realized they were quite different. They are smaller, and the white fur around the eyes, the spectacles, is as distinctive as the moustache. The group size and behaviour was typical. When the juveniles are 4-5 years old they leave the group. Individuals can live up to an age of abbout 20 years.
Leaf monkeys developed in Southeast Asia about three million years ago and have radiated into about twenty living species, mostly threatened. The case of the Indian population of Phayre’s leaf monkey is typical. They are well protected in a few isolated sanctuaries, there are some international efforts at conservation, but the protected areas are small and well-separated from each other. As a result the populations are now quite inbred. The situation is not much better over the rest of its range: Bangladesh, Myanmar, Thailand, Laos, Vietnam and southern China. Much of this region is densely populated, and forest land is being lost fairly rapidly.
The spectacled langur is classed as “endangered” by IUCN. If habitat loss continues, it will inevitably slide to “critical” and then to “extinct”. I have encountered many beautiful and strange species since 2005, when I started to visit wildlife reserves around India. Sadly, a large fraction of them are threatened.