Summer Thunderstorm

A sudden thunderstorm at the end of a burning hot day can lower the temperature by almost 20 degrees. The cooler, high altitude, air can take a couple of days to warm up again. In the middle of our trip to Corbett NP we were caught in this storm.

An odd nest for a lapwing?

While driving along a track in the grassland of the Dhikala range in Corbett NP, we spotted a pair of Red-wattled lapwings (Vanellus indicus) at a nest. They usually nest in scrapes on the ground, but I’d never seen one before. Still, the location in the middle of a track seemed oddly exposed (featured photo). The pair had chosen the grassy part where the wheels of jeeps would seldom reach, so that the danger of accidental crushing of the eggs by passing vehicles was minimized. Lapwings are known to keep guard around the nest and mob larger animals to protect their nests. I supposed that this is the way they ensure that deer or elephants do not crush their eggs (I would dearly 🙂 love to watch two lapwings trying to budge an elephant from its intended path). The very next day I saw a lapwing determinedly stand its ground in front of our jeep, forcing us to skirt it (photo below). We looked for its nest, but it must have been hidden in the grass nearby. So at least with us this behaviour succeeded.

Ground-nesting birds lose eggs to predators, and this is no exception. A count in the grounds of the Delhi zoo showed that over 40% of their eggs are taken by predators, mainly mongoose, crows and kites. It is now known that crows can discover nests by watching humans, so the extreme hands-on process of counting, as described in the article, may have caused more loss of eggs than is normal. Still, even inside Corbett NP there must be a significant number of predators on the watch for eggs. One response from the bird is camouflage: the eggs are the colour of the dust you see here, with splotches of black, which make them hard to spot among leaf litter and grass.

Like many others, I make it a principle not to go to a nest and take photos of the eggs, so that we don’t lead predators like corvids to one. But I kept worrying about the selection of such an exposed site. I later found a report of a pair nesting on the open roof of a bungalow. There was an even older report of a pair nesting between the tracks of a frequently used railroad. I wonder whether V. indicus protects its eggs by active deterrence rather than subterfuge. The very presence of two adults would alert egg-stealers of the location of a nest, even if it is hidden. So it is possible that these sightings of relatively visible nesting sites is no accident. Clearly there is much still to be understood about even such a common species of bird.

The threatened Jackal

We were watching birds in the Bijrani range of Corbett NP when I saw a sleek shape lope past on a parallel path. Our driver-guide was quicker than me, and immediately backed our jeep at speed. “Don’t worry, you’ll get a good photo,” he told me as I tried to focus through the bumps. Golden jackals (Canis aureus) like to travel on human roads, their adaptability is part of their tragedy. They are still seen as not needing the helping hand that we hold out to tigers and leopards, although they are disappearing faster. Our guide was right. The jackal turned with the road it was on, and came to a halt at the junction with the road we’d taken, just perfectly positioned for a close shot. It decided that we were a threat, and abruptly changed direction to backtrack. But there was another jeep ahead of us, so it came back, crossed the road, and disappeared into the growth next to it. I got a few good shots. The afternoon light was terrific, and these were about the best shots of jackals that I’ve ever got. The best of the driver-guides whom I’ve met in national parks in India know animal behaviour inside out. It is a pleasure to be with them.

Don’t you find yourself with some sympathy for underdogs? The beautiful Golden jackals are the underdogs of Indian wildlife, and they need all of our sympathy. Not as charismatic as the tigers or even leopards, not as impressive as the elephants and rhinos, they are slipping through the safety net of public sympathy towards extinction. The invention of key conservation species like the giant panda and the tiger was supposed to buy forest workers some breathing space, as they regenerated the habitats around the advertised species and made it safe for other, less saleable, creatures. Unfortunately, stardom has skewed these projects, and they are now geared towards the big few rather than the whole biosphere. As a result, the jackals of this world continue to suffer threats.

Clever little mynas

One morning in Corbett NP I was watching a herd of elephants walk through tall grass and noticed that a flock of common mynas (Acridotheres tristis) followed them. Sometimes they sat on the elephants, hitching rides on their back, ears, tusks, and even, once, on a trunk. At other times they swooped and swerved between the bulky herbivores. I’d seen them in association with other large herbivores before: gaur (Bos gaurus, the Indian bison), Indian one-horned rhinoceros (Rhinoceros unicornis), nilgai (Boselaphus tragocamelus), and even sambar (Rusa unicolor). I knew something about what they were doing: rendering a service to the host by picking ticks off them, and also keeping an eye on the many insects thrown up from vegetation by the passing of these large animals. This mutually advantageous behaviour is unlikely to be genetically programmed, partly because the birds seem to be able to generalize from one large herbivore to another. In every jungle, the mynas find more than one large herbivore which provides the same opportunity for mutual benefit. If humans did something like that, we would call it cultural learning.

Later that day when I saw a sambar (Rusa unicolor) in the distance with a myna on its back, I didn’t think much more about it. But now, looking at the photo I realize that it was a jungle myna (Acridotheres fuscus), easily told from the common by the tuft of feathers that it has over its beak. So this mutualism between herbivores and birds is deeper. In Africa I’d seen oxpeckers (genus Buphagus) riding on herbivores; it is still an open question whether there is an element of parasitism in this relationship. Oxpeckers are not in the same family as mynas, but may be closely related. So this mutualistic behaviour between some mammals and dinosaurs could have evolved earlier, and the culture could have passed on even though the species evolved into new ones. This may seem weird, but then humans may have inherited the culture of using hearth fires from ancient ancestors called Homo erectus. I wonder whether there are other examples of cultures being preserved for times long enough for biological evolution to disperse it across multiple species. For example, was the use of tools a discovery made so far back in our ancestry that both chimpanzees and humans took the idea from a common ancestor?

Chital

We crossed the last river bed on the way back from Bijrani range in Corbett. This was goodbye. We stopped to see a Woolly-necked stork (Ciconia episcopus), our last addition to the trip’s list of birds. A family of chital (Axis axis) was grazing between the pebbles at the bottom of the stream. A healthy buck (the featured photo), a doe, and two fawns (photo below) ranged slowly over the stones, picking delicately at small shoots. Strange that they would venture here for such slim picking; they must find these leaves delicious.

Chital lie in a genus of their own, Axis, the last remnants of a five million years old twig on the tree of life. Fossil Axis are found from Iran eastwards to Southeast Asia. They are most closely related to the Barasingha (Rucervus duvaucelii, the swamp deer). Once these were common in the Dhikala range, north of this river. But when its homeland was inundated in the 1960s by the floodwaters gathered behind a dam in the neighbourhood, they went locally extinct. The Chital are now only found in India; a landscape with wild chital tells you definitely that it was taken in India. When they become extinct, a five million year old story will come to an end.

Science da kamaal! Posts appear automatically while I travel off net.

A bristled grassbird

Another grassland, another grassbird. We noticed the bristled grassbird (Schoenicola striatus) in Dhikala range of Corbett NP because of its aerial display. It is named for its distinctive bristles above its beak, near the end of the gape line. It hasn’t come well in this compressed photo; you can see it only as a dark smudge just above the beak in front of the eyes. It was nesting season, and its aerial display was different enough from the skylarks’ that it caught attention. It touched down on a stalk of grass and turned its head to look all around as it sang. Then in a moment it had hopped down into the tall grasses in the patch and was gone.

The ground was reasonably wet because of the rains. Perhaps it had built a nest in the grass. It population has declined fast in recent years as wet grasslands are drained and given over to humans. This is the sad fate of most grasslands in our country. In my childhood trains used to chug through grasslands: Chital and Sambar would look up at its passing, while Nilgai bounded through, looking for Acacia to browse on. You would hear stories of yellow-green eyes staring at you from low in the grass. Perhaps a tiger, maybe a leopard. I hadn’t seen one, but enough people had for this not to be a tall tale. The word grassland was not part of the vocabulary. For the lack of a name, they were not set aside for conservation, and nearly disappeared. With them went the tigers, elephants, bustards, and lesser species, like this grassbird.

Now, perhaps with the renewed protection to Terai grasslands, following the success of Project Tiger, these species will find a haven. But this bird may be migratory: flying from its Terai nesting sites to the south and west in winter. Trying to find its true wintering grounds is a little confused by the limits of citizen science. The profusion of birders along the coast has resulted in a large number of sightings reported around the large cities in winters, but it is likely to be more common in the grasslands of Bengal and peninsular India, south of the Narmada, from where it is not reported equally often to eBird. The peninsular grasslands are hubs of human activity, and not protected. At the moment all that is properly established is that the population of Bristled grassbirds has crashed in recent years, and not yet stabilized. That earns it the status of vulnerable in the IUCN Red List, in the slippery upper slopes of the road to extinction.

Science da kamaal! Posts appear automatically while I travel off net.

The tiger of summer

Burning days bring tigers out of hiding. This has been a record breaking summer. We traveled to the protected jungle of Jim Corbett National Park at this time because we knew that extreme heat simplifies the behaviour of tigers. In such adverse conditions a tiger would be concerned only with food, water, and rest. Humans like us had one more need: a connect with ancient times, with nature. Sure enough, as the morning became warmer, there was a movement in the grass, a striped orange, black, and white shape.

All the tigress wanted to do was to walk down-slope to the water. We spotted her as she came down a ridge through tall grass. The slim muscled body was powerful, rendering the steep downhill motion into a graceful slinky walk. I can imagine the fascination of our ancestors, the immense attractiveness of this predator, balancing the danger that it poses. The descriptors attached to tigers in the various Indian languages bring this ancestral memory to us.

A long slow walk, and an occasional look at distant chital. You could feel the calculation in its mind. Do I need food more than water right now? Instincts, you may call it, but not to the sense of self that every animal has. The pauses gave me photos. The featured photo is from such a moment of calculation, its face round like a pot, powerful jaws open, the yellow eyes looking at prey, until it gave in to a greater desire: water. It crossed the road in front of us and walked down another slope.

This tigress must have been incredibly uncomfortable. Tigers evolved in colder climates, and now, in the late anthropocene, as our world comes closer to its end, this one had been pushed to the end of its zone of comfort. She didn’t even walk to the water. She just plopped down in the soft mud and panted. There was a small recent wound in her shoulder. Had she got it in a hunt or in a boundary dispute with another tiger? Our driver, a certified guide, told us that she was twelve years old. She probably had three to four years of life left. The disputes would become more common, and she could even be evicted before her death from her prime territory: shade, food, and water all close by.

After about fifteen minutes, when she’d cooled a bit, she got up and sought water. Further off a mugger (Crocodylus palustris) and a gharial (Gavialis gangeticus) basked in the sun. Those aquatic predators would have engaged my attention on another day. Today my camera did not stray from the tigress. The larger biosphere reserve that Jim Corbett NP is part of will give tigers a route to higher altitudes and more suitable temperatures in coming years, as India warms.

This was her payoff. The hour-long trudge from the deep shade of the jungle, across the long grassland, into the edge of the water was finally done. She settled in like any contented mammal. I had the distinct feeling that a rubber duckie would have been as welcome here as in any bath tub; any excuse to stay in the water would do. She outlasted us in patience. Our morning’s allocated slot in the jungle was nearly over, and we had to leave. When we came back in the afternoon she’d left. There was no shade over the water, and it would have got too warm for her soon after we left.

What wings dare

On what wings dare he aspire?
What the hand, dare seize the fire?

The Tyger (1794) William Blake

Milkweed butterflies, like common crows (Euploea core) and common tigers (Danaus genutia), lay eggs on trees full of toxins. The newly hatched caterpillars then feed on the leaves of these plants and concentrate the toxins in their bodies. The toxins remain through their metamorphosis into butterflies, and make them undesirable prey. I’d assumed that just as they lay eggs on different plants, the adults must take nectar from different plants. I was surprised to find many individuals from both species feeding on one plant. I suppose that there are species of plants whose nectar attracts one or the other, but not both, species of butterflies. Otherwise the crows and tigers would be in competition. There’s nothing wrong with competition, but one eventually wins, and the other has to find a less desirable range. There is no evidence for that happening to one of these species.

A rich ecosystem is full of creatures utilizing every resource, and individuals of one species are a resource for another. The caterpillars are parasites on their host plants, but the adults have reached a sexual mutualism with nectar yielding plants. The plants require butterflies for fertlization, and the butterflies are unable to lay eggs without the sugar that the plants supply. These butterflies have their own parasites: tiny flies (tachinids) and wasps (chalcids). They lay their eggs in caterpillars. The parasitic maggots hatch and eat their hosts from inside. Although I haven’t seen the parasites yet I remain hopeful and ready with my camera; the adult flies and wasps are big enough that I could photograph them. On the other hand, the only symbiotes of these two which have been studied are really tiny: bacteria from a genus called Wolbachia which live entirely inside the cells of the butterflies and influence their reproductive strategies. There is no chance that my camera will ever catch these.

The jungle was full of such lovely small things. The photo of the spider web that you see was taken on a path called thandi sadak (cool road). It was surrounded by fields full of this plant that some would recognize immediately; they grow wild across the hills and are a target for foragers. The spider itself was too small to be seen. There’s a lot of literature on how cannabinoids influence spiders. You can actually see a typical example here: some of the space between the spokes have not been filled in. I’m not sure that spiders munch leaves, but they could be eating insects which have taken up toxins from the plant. Although chital (Axis axis, spotted deer) grazed in neighbouring patches of grass, they did not venture into fields of Grass.

Less spectacular than the crows and tigers, but equally abundant, were these common sailors (Neptis hylas). They have an interesting flight: a couple of wing beats and then a long glide, then again a wing beat or two. I would like to weigh them, because the flight pattern could mean that the wings are large compared to the weight, like a glider’s. They are not milkweed butterflies, and there is no record of them being distasteful or poisonous. That’s why it puzzles me that there are so many of them in the jungle, and there seem to be no predators. A low body weight could also imply that they are too small a portion to be worthwhile for birds to hunt. Perhaps also their fecundity, eggs hatch multiple times a year, keep their numbers high although they are edible.

A dark shape flew into the leaf-litter below the where the sailor was sunning itself. The moment it stopped moving it disappeared. I searched the ground and couldn’t see anything. Then there was a tiny movement in the ground, and I could focus on it. This was a Prosotas butterfly, possibly the common lineblue (Prosotas nora). I always have to look at the lineblues carefully to figure out the species, and the strong sunlight with dark shadows, and the odd angle I was looking at it prevents me from making a firm identification. But this is was a happy sighting: here was a non-poisonous butterfly which took good care to camouflage itself. Even in the photo, you could mistake it for a dried leaf if you just glance across it quickly.

The buffer zones of these protected forests are set up to attract large numbers of eco-tourists, so that residents have a stake in keeping the jungle protected. But since the average person is interested only in large animals, tigers or elephants and deer, there is little opportunity for those interested in small things like insects to observe them. From the back of a jeep I saw only the small creatures that I already knew. Seeing the familiar in a new setting can always show you new behaviour and raise new questions. So I found myself happy even with these limited opportunities.

Night Market, Ramnagar

Our train deposited us at Ramnagar railway station an hour before its scheduled arrival time. Not only was this unprecedented, it was also unwelcome. I certainly hadn’t had enough sleep to be able to spend the day watching tigers. We staggered out of the station with our baggage and into a taxi. I needed a chai, but wasn’t sure that I could get one at this time. I was surprised.

A night market seemed to be in progress right outside, on the sides of the highway that led to Corbett, Ranikhet and further north. One food cart was ready with the usual trimmings: chai boiling in a pan, ready to be poured into the usual thick-walled glass, eggs and bread for a quick omelette, or the packet of instant noodles. The man looked sleepy as he looked up at my phone, and I felt quite as tired as him.

Fruits, a quick meal, and packaged food seemed to be the big thing here. I was slow in interpreting what I saw. I looked for bananas and oranges, a few apples. Food in these jungle lodges can be very good, but usually lack a bit in fruits. I found several carts and distributed my custom between them.

Eventually it struck me that there were too many people on the road. Could they all be going to the jungle? I didn’t think eco-tourism had caught on so widely. I eventually realized that this was a day for a pilgrimage, and people from several districts around here had arrived to visit a temple which stood in the middle of one of the rivers which thread the western Terai before they merge into the Ganga. The number of eco-tourists was miniscule.

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