I’m extraordinarily blind to monkeys. After multiple instances of failing to look closely at monkeys in time to realize that I was looking at a new species, I still don’t pay much attention to them. The bonnet macaques (Macaca radiata) I saw were another example which should wake me up. It was only when I looked at them through my camera that I told myself, “Interesting hair.” A pause, and I asked myself “What do you mean interesting hair?” Irritated, I told myself, “Don’t you see the center parting? Ever seen anything like that recently?” Long meaningful pause. I gulped. “Oh, you mean I’m seeing a different species?”
In my defense, trained naturalists also miss many things about monkeys. It wasn’t till the late 1960s that naturalists realized that both the rhesus monkeys of northern India and the bonnet macaques of southern India were essentially living amongst us; more than half the population of these monkeys live cheek by jowl with humans. Less than half live in jungles. So what is their natural habitat? Some authors have coined the term weed macaques to describe their lifestyle in human-degraded ecologies.
I find it fascinating that the genus Macaca originated in Africa and radiated into the existing 23 species in about 5 million years while they spread across the old world. This is an incredibly close parallel with the Hominins, whose radiation and spread started at about the same time. Macaques can now be found all over Asia and in parts of southern Europe. While the Hominin family tree collapsed down to H. sapiens around the time of the last glaciation, Macaca diversity remains (although now under stress). There is a core social structure in Macaques which is preserved across species. This involves the formation of matrilineal groups with strict social ordering separately amongst the males and females, and of sub-adult males generally leaving their birth groups. The Hominin social organization is different (as we have no difficulty in recognizing), but was also preserved across species.
Bonnet macaques live in peninsular India as far north as the Godavari and Tapti rivers. I saw people leave peanuts for these monkeys. Apparently they are sometimes given bananas too. They seemed much less aggressive than rhesus monkeys, and are reportedly losing territory to the latter. Genetic evidence shows that they evolved separately, and paleo-climate data read along with genetics then tells us that they initially occupied different ecological niches. With the spread of agriculture after the last glaciation they both became weed macaques, and therefore are now in direct competition.
Are they really threatened when trees are cut down? In the last 60 years repeated observations have shown that this depends on simple factors. Are the monkeys living quite separately from humans? Do they move away when a non-threatening human advances towards them? Are there natural predators or other predators like feral dogs? Are they largely left alone by humans? If the answer to several of these questions is “No”, then the group of monkeys is likely to disappear within a few years. By this measure the bunch of monkeys I photographed on the outskirts of Thattekad sanctuary were endangered. Although the IUCN red list says that it is not threatened, bonnet macaques have almost disappeared from many towns in recent years.