When The Family told me to look out for grey hornbills, I was surprised. We have seen and photographed Indian grey hornbills nesting in our garden, and I didn’t think I would specially watch out for them. “These are Malabar grey hornbills”, she explained. I looked it up. They are the smallest of the Indian hornbills, being less than half a meter long, lack the casque of the other, and have somewhat paler beaks. We heard the raucous calls of one in our first day in Thattekad. Then, from the lava dome in Urulanthanni we had a wonderful view of a couple of these Ocyceros griseus. I saw one eating a fig in the usual Hornbill style: first holding it in the tip of its bill, and then after throwing it back towards its throat, it raised its head and opened its bill to catch it. I also saw it regurgitate some food and eat it: below.
The large number of hornbill species across Asia probably radiated out from India after it collided with Asia and its rainforests spread across a new continent. In fact, the hornbills could be among the oldest birds in India, probably having come here from Africa around 50 million years ago. When it comes to discussions about original Indians, hornbills beat all humans by about 50 million years, less some change. Hornbills began to diversify into fruit eaters, and remain omnivorous but largely fruit eating even today. Later, one of the Indian lineages repopulated Africa. Modern African hornbills are descended from these.
It is relatively easy to study the nesting of hornbills. They are monogamous, and choose to nest in the same hollow in a tree year after year. Whenever I see a hollow in a tree with a sharp round opening, I wonder if this is a potential nest for hornbills. Every year, the pair clean the hole in the tree where the nest will be. The nesting begins at a time when the forest is at the peak of its fruiting season, around the middle of February. Then, after laying eggs, the female seals herself and the eggs into the nest using her fecal matter, which is rich in seeds. The nest has a slit for breathing, feeding and sanitation. Nest repairing is left to the female. The eggs take about 40 days to hatch, and another 45 days pass before the fledgelings emerge. The male forages widely to bring a variety of fruits and insects to the female and the hatchlings, and thereby manages to disperse seeds. The hornbill is therefore a keystone species in the forest. Divya Mudappa spent a few pleasant months in these jungles making a checklist of fruits eaten by the Malabar grey hornbill. Several of the plants which the they feed on are classed as vulnerable in the IUCN red list, and several others have not been evaluated.
The Indian grey hornbill and the Malabar grey hornbill overlap in a very small range. Since they compete for the same resources, I wonder about the outcomes.
At a place called Urulanthanni near Thattekad is a rock poking out of the surrounding rain forest. The area is a ecological hot spot. The dense canopy of the forest holds a very large variety of endemic birds, which are invisible from the ground. The rock provides a great vantage point from which to view the activity in the canopy. In fact, as you can see in the featured photo, the canopy itself is a grand view.
While walking in the forest I’d noticed basaltic rocks poking out of the ground at various places. So the whole rain forest here has been formed by sedimentation and erosion of the volcanic rock. This knoll that I stood on was a rougher rock. On the surface I could see a flowing texture created by weathering. You can see this in the photo below. But when I looked at a broken face in the rock, as in the photo above, I could see the grainy texture of the rock. It seems that the rock here is a mixture of two kinds called gabbro and syenite. Both have this texture, but are different in the minerals that they contain. So this giant rock must have been created by a separate upwelling of magma within the volcanic rocks underlying the land around us. The red insect is the nymph of a bug which I saw later.
How did inhospitable rock become the bed of a rain forest? Observations on Mount Saint Helens has given us a wonderful insight into how biology covers geology. Could I see the beginnings of the cycle on this dome? Almost certainly the bare rock was covered by bacteria. But the smallest things I could see were mosses. I regretted not bringing my macro attachment. I would have got wonderful photos here. At the next level of organization, I could see soil blown into little hollows in the rock, as in the photo above. Was this enough to support plants?
It seemed that it was. I could see clumps of bushes growing in these thin mats of soil. As they grow and shed leaves they add to the soil. They also present a barrier to winds which cause the air to drop soil around them. Right at the exposed top, the process of bootstrapping the creation of soil is slow. But just behind the flat top, it proceeds faster, accelerating even more as you go down the slope. In the photo above you can see the scant bushes at the flat top growing in a thin mat of soil, and the larger thickets of bush lower down. You can also see a few trees which have taken root in the upper slopes. Eventually, the bacteria, moss, bushes and trees will erode the stone into soil, and this dome will be covered in vegetation!
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.
I woke up in the morning to the cacophony of Mumbai’s crows, and found myself missing the homestay in Kerala where I spent the last few days. The morning’s sounds there were the last hoots of owls and the first notes of warblers. The house was near a little creek off the Periyar river which is too small to appear on maps. On my first afternoon’s stroll down to the creek I took the featured photo. In the three days that we spent there, I didn’t see anyone take the boat out, although it was in too good a repair to have been abandoned.
God’s own country, as the pompous advertisements of the 1990s said of Kerala, is a little too crowded and prone to service strikes to be what it claims. The minibus which took us from the airport to the banks of the Periyar river passed through an unending stretch of one and two storied houses surrounded by trees, and interrupted by busy crossroads where the humidity and heat seemed to have encouraged the mushrooming of small shops. It was only when we crossed the bridge over the Periyar river that we saw the first bit of landscape which justified the advertisements’ tagline. The beautiful landscape which you see in the photo above was full of the birds whose calls I find myself nostalgic about.
The bird sanctuary across the bridge is named after the legendary ornithologist, Salim Ali, who, in the 1930s, recognized this area as a hot spot of biodiversity as intense as north-eastern India. This was an idea ahead of its time. It wasn’t until the 1980s that the uniqueness of the ecology of the Western ghats was more widely appreciated. Sanctuaries and protected forests were set up. If it wasn’t for such measures, a passing tourist like me wouldn’t be able to spot over a hundred species of birds in three days in this place. Even by a little village pond on the outskirts of the sanctuary, like the one whose photo you can see above, one sees over a dozen species of birds. There are dangerous mammals in the jungle, of course. Elephants are in constant territorial conflict with people. Pugmarks of a tiger have been seen once. But, by and large, this rain forest and the banks of this river are places for quiet walks.