Archive for the ‘Night Life’ Category
Naan paer Claire. Naan vowvall araichee… I am Claire. I research bats.
It has a confessional ring to it, to my ears, every time I say it; and I do sometimes get looked at as though I’m insane as I try to explain why I try to study these animals that many people consider ‘useless’ and rather sinister, that can fly, live at night, and find their way in the dark better than most of us can in daylight. But to quote Hunter S. Thompson, ‘If you’re going to be crazy, you have to get paid for it or else you’re going to be locked up.’ The challenges and rewards of studying these elusive animals keeps me committed to wildlife rather than simply committed, and pays me to travel to boot. I consider that quite a bargain. I’d also like to try and share with you my ever-growing fascination with bats, and why I want to understand their world. Also, I’ll include cute bats photos of species we’ve caught in Valparai; all together now, awwwwwww!
In their defence, bats aren’t ‘useless’ at all; even if you accept the premise that we should only study species that benefit people (which I don’t), they do many useful tasks under the cover of darkness. In fact, they were recently voted the world’s fourth most useful natural group (after bees, fungi and protozoa) in a public debate at the Zoological Society of London. (The merits of determining an animal’s usefulness by public debate can be criticised elsewhere, but here they supported my point!) Bats can eat up to 3000 insects a night, including mosquitos and midges – a good thing, I think anyone who’s spent a lot of time doing fieldwork will agree – and in many places they have been found to eat crop pests as well, benefiting US agriculture to the tune of at least $3.7 billion a year. Even the tropical fruit bats, so often persecuted for eating fruit in orchards, play their roles; pollinating and dispersing the seeds of rainforest species, helping to keep these vital ecosystems intact. And as for the bats that everyone asks about – the vampire bats that evoke ruined castles, caped intruders and pale-skinned damsels in distress – well, there are a whopping three species that drink blood (out of about 1,200 bat species worldwide) and they all live in Latin America, where some feed on cattle, some on birds and goats and some on any sleeping mammals; so in India, the only bloodsuckers you need to worry about are the leeches!
As I have learnt more about bats during the first few months of my PhD, I have been amazed by their behaviour, and their unique place in the natural kingdom. There are over 1200 species of bats, and more are being discovered all the time, making them the second most speciose mammal group after rodents. They are, however not closely related to rodents at all; in fact, bats are considered evolutionarily far closer to carnivores, ungulates and cetaceans, although there is still some debate on their evolutionary past. They are the only mammals that can fly, and insectivorous bats echolocate to navigate in the dark and find their prey, making high frequency calls and listening for the echoes that bounce back. Certain species can navigate so precisely that they can pluck a spider from its web without getting tangled. Sometimes, people with good hearing can hear their low frequency social calls; if we could hear their high frequency calls, they would sound as loud as a fire engine’s siren! It is these calls that researchers record with bat detectors. A recent experiment showed that bats even manage to spread culture through calls, with naïve bats quickly learning to associate novel frog calls with food as they heard their neighbours hunting and eating in response to these calls (and presumably ‘ooohing’ and ‘aaahing’), even when the call was from a frog they wouldn’t ever eat. (Frog lovers; no frogs were killed in this study. Read about it in the links at the end of this blog!)
Bats can live for well over twenty years, and my colleague Emma’s work in the UK has shown that in one species at least it is not until they are 4 years old that 100% of the cohort are breeding (think about what that means for any population decline). Mothers produce one pup at a time, generally only one or two a year depending on climate, feeding them on their milk; some species fly around with the baby attached to them, while others leave the babies in a group while they go to feed, and then return and identify their own pup out of potentially thousands of others. They have complex social lives, interacting with many other bats in the roost; vampire bats live so closely together that a full bat will feed one that has returned hungry from a night’s hunt, knowing that should it return hungry one day its roost mates will feed it in return. This is a very rare case of true reciprocal altruism to non-kin in the animal kingdom – although it appears it only occurs between females.
Bats live in trees, caves, tunnels, mines, house roofs and even make tents from palm fronds. Some Lophostoma bats live in termite mounds, possibly sending chemical signals that induce the termites not to attack them; the precise mechanism is still unknown. They feed on a range of foods from fruit and nectar to arthropods, frogs, fish and sometimes other bats, and some even take mineral supplements; a research team recently found that some fruit bats in Ecuador lick mineral clays to counteract the toxins found in energy rich unripe fruits.
We have so much more to learn about these fascinating creatures, but we may be running out of time. In addition to threats from habitat destruction, hunting for food, medicine and fun, being killed by air pressure changes around wind turbines and the disturbance of mines and caves, an even more sinister shadow is spreading. Like Colony Collapse Disorder in bees, and Chytridomycosis in amphimbians, a killer disease is threatening bat populations across the USA and possibly the world. White Nose Syndrome (WNS) has up to 97% mortality rate in some bat roosts, and has so far killed at least a million bats – a huge number considering that this disease was first documented in 2006. This disease leaves suffering bats with characteristic white fungal growths on their face, and they usually die soon after developing these symptoms. This is puzzling as most fungal infections do not kill their host. So far researchers have discovered that bats found dead from the disease tend to be in very poor condition, often found dead outside the roosts that they use to hibernate in for the cold Northern Hemisphere winters as if they had gone to search for food, so one theory is that the fungus irritates the bats and wakes them from hibernation causing them to fly around and use energy when food is scarce. The bats’ immune systems may be weaker when they are hibernating, allowing the fungus to take hold; or an as yet unidentified disease may be knocking out the immune system and killing the bat, with the fungus opportunistically taking hold.
Whatever the cause, White Nose Syndrome is being taken very seriously in the USA where it has emerged. The problem is how to tackle it. While in lab conditions simple fungicides such as Athlete’s foot powders seem to kill the fungus, the treatments can kill bats and possibly other cave life. So far, people are trying not to spread the disease further by thorough disinfection when entering and leaving caves, and many caves are closed to the public; but some bat species migrate hundreds of kilometres, so can potentially spread it across huge distances themselves. It has now been found in 14 American states and 2 Canadian provinces, and even – possibly – in Europe. Researchers in Europe have found bats that exhibited the characteristic white nose and tested positive for the fungus Geomyces destructans, the same fungus found in the North American bats, but appeared otherwise healthy. This has lead to the hope that European bats may be less susceptible to the disease, or have a lower mortality rate. Because the mortality rate is serious; if the current mortality rates hold, then America’s most common bat species will be extinct in the eastern US in twenty years, a terrible loss for America, and for the world.
Fortunately, WNS is unlikely to spread through much of India as the fungus prefers temperatures below 20°C and spreads through roosts where bats are hibernating against the cold. In the meantime, we aim to find out a little about what species the Western Ghats supports, their social lives, habitat requirements, genetics and calls, and how any parasite borne diseases spread through these populations. I also hope in coming years to assess their ‘usefulness’ in terms of eating coffee pests.
In our pursuit of these wonderful little animals, we’ve faced many and diverse challenges. We’ve had nights with no bats. We’ve had to climb down rope ladders to get to the bats, and waded through thigh high water full of bat dropping, weeds and no doubt horrible parasites to position the harp traps (sorry Occupational Health and Safety!). We’ve run away from elephants, and stood with our hearts in our mouths as Anand, our incomparable field assistant, shooed away huge male gaur as if they were naughty goats. We’ve fallen in innumerable rivers, got hideously muddy and had our legs mauled by leeches. We’ve sat at a roost while Rhinolophus rouxii flew up to our harp traps and wheeled away at the last minute, and sworn in frustration as even those that fell in to the bags managed somehow to fly back out again, refusing to sit and roost quietly like most of our species. We’ve got drenched in thunderstorms, sunburnt (well, we sometimes have to go out in daylight) and even had Nilgiri langurs try to urinate on us from a great height. Our GPS messed up and eventually died in the middle of an acoustic transect, as we stood in the dark and howled at the gods of malfunctioning technology. We’ve been overwhelmed with awkward questions when going for anti-rabies shots, including being asked ‘where do you want the shot…hand or buttock’ in a room full of gawking strangers. And I won’t even go into our problems with the forest permits…except to wonder how we were meant to study bats with a permit that allowed us into the reserve from 6am to 6pm.
But yet there have been many highs as well. We’ve caught close to 200 bats, collected disgusting but scientifically fascinating parasites from over 100 of them and recorded many of their calls. We’ve also collected lots of rather malodourous bat faeces, which we can use to see what they’re eating. We’ve seen some lovely species, from the big, gentle fruit bats Rousettus leschenaultii to the funny little Rhinolophus lepidus with their yellow noseleaves. We’ve also enjoyed some beautiful country on our transect walks – when we could take a moment to look up from the acoustic detectors and recorders and gaze up at the fireflies flashing in the dark trees, silhouetted against the night sky. We’ve been privileged enough to watch families of elephants feed and sleep, to see a leopard cat look into our eyes from just a few metres away and to meet some truly wonderful people in the course of our work. Despite the many scars we’ve sustained, I want to leave you with another Hunter S. Thompson quote – ‘So we shall let the reader answer this question for himself: who is the happier man, he who has braved the storm of life and lived or he who has stayed securely on shore and merely existed?’
For further reading, here are some interesting links:
It was drizzling in Valparai when I started to Chalakudi late in the evening after I stopped there to have a cup of tea. I was not in a hurry, driving slowly I reached Malakipara Forest Check Post at around 6:00 pm. I stopped the vehicle in front of the barricade and went inside the office. A forest guard asked me in Malayalam, ‘where are you going’?
I said ‘to Chalakudi’.
‘Do you have plastic bags in your car?’
‘No, I don’t have any’.
‘What is the purpose of visit?’
‘I am going to attend my friend’s marriage there’.
‘How many people are in the car? Who is driving?’
‘I am alone and driving myself’.
‘Show your license’.
I opened my wallet, took out the half torn license and gave it to the forester.
The forester leaned sideways from his chair a bit and looked at the vehicle’s registration number and entered in his huge ledger full of details of vehicles passing through that check post. He filled a verification certificate and asked me to sign on it. He returned my license and said, ’don’t stop anywhere and give this certificate at the other check post ’.
It generally takes about 3 hrs to reach Chalakudi from Valparai. It was a deliberate decision to start late in the evening from Valparai so that I can see some wildlife while driving through that pristine rainforest. I had driven through this forest during the day few times but never travelled at night. I drove slowly in that twisting and curving road towards Vazachalal rainforests. It was late in the evening and sky full of monsoon clouds, however, there was ample light and there was no need to put on the headlights.
I entered a forest road after few minutes. I leaned forward and looked up through the glass. Tall trees by the side of the road touching each other canopy. I was driving slowly in second gear and the maximum speed was only around 20 to 30 km/hr. It stared drizzling slowly. I stopped at one place where there was an opening of canopy due the passing Electric pylon. Hill mynas, Common mynas, Racket-tailed drongos, and Chestnut-headed Bee-eaters were flying around and catching the winged termites which emerged recently. On the other side of the valley there was a breathtaking view of monsoon clouds passing like waves on rainforest canopy. The scene reminded me of a photo by Kalyan Varma showing similar view.
After watching them for a while I started again and entered a road closed by rainforest tree canopy. Light was dim so I put on the headlights. Roadsides were clad with different varieties of ferns. They look beautiful from every angle even at night.
It was at that moment that I noticed a movement by the side of the road. It was a small frog that jumped from one end of the road and almost cleared the width of the road just by two jumps. One more jump and it would have gone into those ferns and other plants with leaves of different shapes and sizes. But it didn’t. It stayed right there. I slowed down a bit, swerved away from the frog and went past. There were quite a few on the way. I saw another frog but this one did several jumps to reach even at the middle of the road. The width of this road was about 4 to 5m on an average. I had to be a bit careful while passing this type of frog. I had to drive past this frog keeping it in-between the two tyres and hoping that it doesn’t move from the place where it stopped. After passing few more frogs I put off the headlights. Although the natural light was less under the closed canopy it was still possible to see what was in the front.
It was a Sunday but surprisingly there were not many vehicles going towards Athirapalli – a waterfall – a major tourist destination. Obviously it was too late for tourists to go there at this hour, but there were quite a few vehicles going past me towards Valparai. In all the vehicles that passed by, headlights were on and they honked at me as well while passing. I had to wait by the side of the road to make way for them. On one such occasion my car stopped. Before turning it on I waited there for a while. I came out of the car and stood by the side of it. I was surrounded by the cacophony of frog calls of varying resonance.
The calls of the frogs were everywhere in that forest. It came from the ground, from mid-story, and some appeared as if it was coming from top of the trees. It was completely dark then. The entire rain forest around me was alive with these frog calls. There were so many varieties of frog calls. Some sounded like, Tik..Tik..Tik..with short intervals between the sharp Tiks, some like Tuk..Tuk…Tuk..as if some one was knocking on the door. Suddenly I got a start when I heard some weird call that sounded like, KRRWakk. I looked around and I heard that same call again and it came from the ground and it was a loud… ‘KRRWaak..kak..kak..’.Then I realized this is another frog and must be calling very close by as it was loud. There was one more similar call coming from a bit far away and I could only hear the first note and the last two notes was very faint and fading away. There was another interesting frog call. The call notes were loud, sharp, and the time interval between the notes was quite uniform. This monotonous call sounded as if it was falling from the top of the tree….TUP……..TUP……..TUP…….. It was like water droplets falling from the tap into a bucket brimming with water. I leaned on the car and closed my eyes facing the canopy. All I could hear was…
……Tik..Tik..Tik…Tuk..Tuk…Tik..Tik..TUP…Tik..Tik..Tik…Tik..Tik..TUP…Tik..Tik..Tuk..Tuk…KRRWaak..kak..kak..TUP..Tik..Tik..Tik..Tik..Tik.. Tuk..Tuk… TUP… Tik..Tik..KRRWaak… Tik..Tik… Tuk..Tuk..Tuk..Tik..Tik..TUP… Tik..Tik..Tik…
What an amazing feeling to be alone inside the rainforest at night and listening to this frog music! Rainforests never sleeps, I thought, birds and cicadas give life during the daytime and it is these frogs that keep the rainforests alive at night, especially during the monsoon. This momentary enjoyment came to an end when I felt a Tup..on my forehead. This time it was a raindrop.
I started my second gear journey through the rainforest again. It was not a heavy downpour but I had to close my windows to avoid water dripping in. Soon rain stopped but it was replaced by a thick fog. I had to be even slower this time. I was thinking about the fate of those jumping frogs. ‘Even if I don’t want to drive over it I can’t do much in this fog’. Who else is going to drive slowly like me on this road? People will think I am mad if I ask them to avoid driving over frogs and stop for them to cross the road, I thought.
It was around 9 pm and I was passing through Oclandra reed forest. I opened the windows and here insects subdued frog calls with their loud and continuous chirping. There was fresh signs of elephants on the road. Bamboo shoots were strewn along the road for a short distance and I noticed fresh dung. No vehicle had passed me for more than half an hour. A slight sense of panic surrounded me, but it was gone the instant I noticed a bunch of tourists on the road. They were dancing in the middle of road to some song blasting from their vehicle which was parked by the side. As they noticed my car they moved a bit to make way and while I was passing them they whistled and shouted.
Few kilometers passed and there was a small village. Here there was more Krok…Krok…Krok and less Tik..Tik..or Tuk..Tuk..May be different types of frogs, I thought. This Krok was non stop without any pauses. But this was only for a short distance, once the forest started, I experienced the same symphony from the rainforest frogs again.
As I was driving, I noticed something long – like a glittering stick by the side of the road. I stopped and reversed the car and came near to that and it was a snake. It was there lying with its raised head as if it is going to catch something. And then I heard a vehicle behind. I quickly opened the door and stepped down and stamped my feet a couple of times on the ground near the snake. It immediately turned and slithered away into the forest floor. I had to be quick to get into the car and moved ahead a bit so that the other vehicle could pass. Again it was the same tourist vehicle and again they shouted as they passed by.
I was not pleased by what happened. Forest roads should be forest roads I thought to myself. It shouldn’t be flat and wide like in the plains. A good road inside the forest means death of several frogs, snakes and many other animals. Forest roads should have a lot of potholes, speed breakers, and preferably kachcha. Suddenly something came to my mind. While I was travelling through this forest wherever the road is not in shape with lot of potholes I didn’t see many frogs jumping in front of the vehicle. But in a flat tarred road I saw many frogs jumping around. So a good road in a forest is good for tourists and others, but is not so good for forests and its animals.
By this time I was nearing Vazhachal Check Post. After completing the necessary formalities with the foresters I started my journey towards Chalakudi. Road from here was wider, but still went through forests for some distance. After that there were several hoardings advertising on how cheap it is to stay at their hotels. There was more Krok..Krok..Krok..here and very few Tik..Tik..Tik or Tuk..Tuk. Not only that, but the calls too were coming from far way since the road is wider. I changed the gear from second to third and to fourth. I said to myself that I will restrict myself as far as I could by not traveling on this road at night time, for the sake of the frogs.
The week began with a meeting with a manager that makes us want to take stock of the direction of the restoration program even more. How can considerations of conservation and restoration, specifically retaining natural services that existing ecosystems provide in these landscapes instead of further converting them to monoculture plantation crops, become a part of routine plantation management decisions and operations?
The peak of the monsoon seems past. Still there is some time and some saplings left in our nursery for a last round of planting in the restoration sites. So we spent the next day sorting saplings—about 100 for each of the four sites this time. We had another enthusiastic volunteer to help, Karthik Teegalapalli, and so we could get going right away. Started with the Varattuparai and Old Valparai sites, then Iyerpadi Top, and finally at Murugalli Candura.
The weather was perfect. Not too much rain while pitting and planting in the mornings, with some showers later in the day. Our team leader Anand made sure that everybody was doing what they should be doing to mark yet another successful and fulfilling planting season.
Later in the evening, we drove to the “seen god” place. On the way, a lovely carpet of tiny white orchids on a tree branch and some more interesting epiphytes caught our eye and we stopped to take a few pictures.
Passing a trail through tea fields, we saw a Black-naped hare grazing on the meadow-like turf at the edge of the tea. At the same time, a dash of red caught Jegan’s eye and this turned out to be a Stripe-necked mongoose. As we watched, the mongoose went right past the hare, each absorbed in their own lives, and paying little attention to each other—a case of harmonious co-existence between a small carnivore (predator) and a herbivore (prey).
A lovely play of mist, clouds, and rain in the Sankarankudi Valley made our evening. And on the mist and rain-wetted slope: beautiful Impatiens flowers!
And then, a night drive! We were lucky to spot two brown palm civets, a few Large Brown Flying Squirrels (including two glides and what looked like a young one), an unidentified eye shine in the understorey, a sounder of wild pigs, a herd of gaur and many black-naped hare. The first brown palm civet we saw was resting curled up in the fork of a tree branch. As we watched and took a few pictures, it looked up at us and then, rested its head down again. We left the scene with the civet still resting and glad that we had not disturbed it from its cozy notch.
And then on Friday afternoon, returning from the Iyerpadi Top planting, we watched lion-tailed macaques (LTMs) making their weekly visit to the temple! Our LTM watchers, working along the main road to protect the monkeys from speeding vehicles and educate tourists, told us that these smart animals had learnt to come near the temple every Friday. As people would come for pooja and break coconuts here, some LTM may get a snack. Yet, this is a habit and habituation that is better broken and our watchers, Joseph and Dharmaraj, are trying to educate the temple visitors. There are plenty of jack trees in fruit and it is wonderful to watch the LTM feeding on the jackfruit in their arboreal life.
And finally, at the end of the week, we had to go for another meeting… but the one hour long drive was nice. To be woken up by the sound of the wing beats of the Great Hornbill, watching them duet and feed each other, the Nilgiri langurs, a black eagle, a crested serpent eagle, and more impatiens adorning the rock faces and mud banks…encouraged to grow by the water seepage…
What lessens our enthu are the meetings and the pointlessness of planting a few 1000 trees when about five times that is being cleared or degraded at the other end at the same time, or when we find a dead animal like this sambar floating in the reservoir without actually becoming a meal to a hungry predator which pulled it down….
What keeps us going is the possibility of the wildlife sightings whenever we go out.
Of course, the usual melodious Malabar Whistling Thrush at dawn and on cloudy days through the day, the Rufous Babblers coming to roost in the mango tree in our neighbour’s yard, and the sawing sound of our friendly neighbourhood leopard at nights are testimonials to a not-so-bad an environment we are living in.
Just another night in the field…just going to check a cave…or so I thought!
How many animals can coexist in a small cave?
When we reached the cave the bats were flying around, inside the cave. It was time for them to stretch their wings before going out. Some were settling upside down to the sealing and then flying again.
A big frog was resting on one rock. As I approached it moved a few centimetres and then again stood still!
Suddenly I noticed an eye shine at the back of the cave. It was a scared mouse deer! It looked at as and then went deeper into the cave. As I was taking random pictures, trying to “capture” the flying bats, I somehow managed to take a picture of all 3 of them!!!
Later we found a spot outside the cave were we could observe and record the bats flying out. The bats started their busy night! In and out of the cave… and then in and then out again! Minding their own business, without caring about the strange creatures that were sitting close to their air-path! After a while the mouse deer shyly came out of the cave…stopped for a second to look as well, at the bizarre creatures that had worried it earlier and then carried on with its night… I guess hoping that when it comes back everything will be back to normal!
Some more time passed and I felt water dripping on my head! Then a few seconds later I saw on the branches in front of me a mouse. Quickly running across the branches, releasing the water droplets stuck between the leaves.
The bats carried on with their usual routine and soon it was time for us to go… thinking that since all this happened during only one hour imagine what was happening during the rest of the night!