Fog factor increases Tiger Straying problem in Sundarban

Sundarban tigers stray-out of forest and enter into the adjacent villages, since time immortal. They mainly enter in Samsernagar, Kumirmari, Hemnagar, Kalidaspur, Mitrabari, Rajat Jubilee, Baganpara, Satyanarayanpur, Amlamati, Gobindapur, Hentalbari, Satjelia, Luxbagan, Lahiripur, Sadhupur, Hamiltan, Dayapur, Pakhiralaya, Dulki, Sonagaon, Bijoynagar, Bali and Mathurakhand of Gosaba Block and Kultoli, Jharkhali of Basanti block etc.

The outs cart apart, the denizens of core Sundarban goers have been facing tiger attacks even as they are the frequenters to catch fish, crabs, tiger prawns or fuel wood in the rivers and estuaries. In the span of 11 years  (2000-11) 73 people have lost their lives to tiger attacks, 60 livestock has been mauled and 88 times tiger stray outs have been recorded; out of which there 65 were village trespassing. There might be slight transformations in the numerical fact, but the question lies in something more profound. Tigers are inhabitants of deep forests and do not generally discard their habitats. If irritated, they delve further into the forest. Although there are some anomalies yet all around the world, every tiger conforms to this rule more or less. Then why is it that the tigers in Sunderbans act otherwise?

It's imperative to know a bit about the background before heading to further discussion. Based on sources, the longevity of the Sunderbans is around 7000 years. Before that, the sea was spread far north, till the Himalayan foothills, a region with immense rainfall. Several rivers jumped down the mountains at tremendous speed towards the sea, thus forming deep forests and riverrine grasslands. Let us suppose that the origin of the four-footed nemesis was in Northern China, Siberia or further north, meaning in the freezing regions. As matter tends to shift from its cold state to warmer one, so does the animal. Therefore we may conclude that our tigers also did the same–travelled southwards from the frosty regions. In order to keep the length of the essay abridged, I am not going into the history of tiger population in other countries of the world.

Now where will they go? They were confronted by the Himalayas. Gradually through the nooks and crannies of the mountains, tigers began to descend further south after entering Nepal and N.E India. They were spoilt for choices – on one hand, were the expansive forests and grasslands at the Himalayan foothills and on the other, the abundance and diversity of preys. One might assume that there was a huge tiger population at the Himalayan foothills then. They crowded Assam, Arunachal Pradesh and all the other N.E states; North Bengal being the chief and notable of them. The tigers spread their claws in India, through North Bengal, Bihar, Uttar Pradesh and present day Uttarakhand.

Historically, soon after this, the entire Himalayan landscape underwent an evolution due to volcanic eruptions. Vast stretches of land appeared; only the present North Bengal portion survived. Most probably after the Himalayan restructuring and change in the river course, man started dwelling in this area resulting in its prosperity. Therefore, the region was coined as ‘Navadweep’ or the new island. The geologists would be able to reflect better upon this issue.

Anyway, the sea shifted course to its present position. What is to happen to the rivers now? They have to meet the sea but how? This is a flat plain without any undulation! All the rivers therefore began to, at first, move in the middle course and gradually flattened out towards the lower course while fusing into the present Bay of Bengal. This resulted in the growth of marshy swamps all around Bengal further giving birth to vast forests. Riverrine grasslands began to develop and several herbivorous animals started to take shelter in these forests. This spelt happy hours for the tigers, since they could roam and kill at will. The Panthera tigris clan began to get the better of Bengal. But one has to remember, at this point that they hadn’t yet ventured into the mangrove forests of the Sunderbans. And why should they? The mangroves were infested with saline waters, tidal waves and suffered from the absence of grasslands. Hence they did not attract herbivores, resulting in the absence of food for the tigers. Also there were the prickling pneumatophores under the feet. The tigers weren’t fools to bargain this lifestyle against the one they were already enjoying. Nowhere in the world, apart from the Sunderbans, did the tigers dwell in mangroves. In fact, the area upto Piyali was teeming with river marshes. There was an abundance of forest and tigers used to live there uninterruptedly. There was no dearth of herbivores either – Swamp Deer, Water Buffaloes, Barking Deer, Sambhar, Hogs, Leaf Deer, Wild Boars and lots more. This was all before 1775; hence history. All the mess started after this.

The problem took when the British Government handed over the Sunderban grant to 144 zamindars. Thereby began immense forest alteration beginning with the grasslands. About 10 thousand sq. km. was severed. The deforestation program went on for several years. The mangroves were much down towards the sea! Several species of the herbivores became extinct due to receding grasslands. Only the tigers, deer, wild boars and monkeys (Rhesus Monkey) survived because of their tremendous adaptability. But where will they go now? The deforested areas are inhabited by humans and they have started farming profusely! Thus the creatures were forced to cross over the river and land on the coastal mangroves. They had to compellingly accept the mangroves as their home and had to adapt too. This is what I call ‘Forced Habitation’. The king of Sunderbans is the victim of circumstances as the primitive Jarowa, Sentinel, Ongi, Sompen and other aboriginal clans of the Andamans. They are still somehow surviving after battling with the pitiless Nature. The Sunderbans have never been the favourite home for the tigers and nor is it today. And after analyzing the nature of tigers, mangroves can never be their accepted habitat.

Above this, there was the political fiasco. India got separated and Bangladesh received a huge chunk (about two thirds) of the Sunderbans. That portion is called the Eastern Sundarban or Bangladesh Sundarban. Our part called the Western Sundarban or Indian Sundarbans. The size of the Indian part is 9500 sq. km. approximately, out of which 5240 sq. km. was already cleared. Out of the remaining 4200 sq. km., a most 1680 sq. Km. (40%) is covered with water. Hence, the remaining land area is not more than only 2500 sq. km. approximately. One has to remember that the coastal forest (about 35%) of this land is extremely saline and hence there is no vegetation, lack of which results in unavailability of deer and other herbivores. Thus, the tigers are reduced to live in a restricted area of about 1600-1700 sq. km. Moreover, the North- Western part of the forest is inhabited by humans; disturbed area according to the tigers. Also, the banks along the fishnet area are disturbed due to incessant human passage. About five lakh people are directly or indirectly dependent on the forest.

2585 (area including water), is the Sunderban Tiger Reserve, a protected zone. Though the perimeter is huge, tigers are allotted only about 1550 sq. km. (excluding water). Adding the South 24 Parganas, it might at the most be 1700 sq. km. If the tigers wander off mistakenly it spells trouble. Previously this difficulty was faced only in the northern part of the Sunderbans but now it has spread to the west also indicating the South 24 Parganas. This wandering off of the tigers is termed as “Straying”. The term is used not only for tigers but for any wild animal displaying such behaviour. The same problem persists with the Rhino, Gaur and Leopard of the forests of North Bengal. The elephant is an exception because it is nomadic. They cross villages, towns and city streets for travelling from one forest to another. Therefore in case of the elephants, the word Straying is inapplicable, as they fall under “Migration”.

Now let us take a look at the Tiger Project. The 2585 sq. km. area is dissected into two parts. The upper 1330 sq. km. is the Buffer area. This region is highly pressurized by human activities, especially tourism. The noise of tourist boats, sound systems, mike etc. continues to create problem here. Therefore it is nearly impossible for the tigers to stay permanently in this Buffer area. But in the hindsight, this Buffer area can actually be a better habitat for the tigers, because of the availability of less saline water in the upper areas, resulting in the amplified number of grasslands and herbivores. Further south, water is not fit for consumption due to higher salinity factor of sea water. Reputed forester and tiger researcher late Mr. Kalyan Chakraborty has pointed out that excessive consumption of saline water causes fatal reactions in the tiger’s liver and stomach. Therefore the tiger tends to lose temper with age and physical uneasiness results in decreased patience and preying skills. It is then that they transform into less slogging man-eaters. So it will spell into heightened trouble.

The Core area of the Sunderban Tiger Reserve, excluding the Buffer area, is only 1255 sq. km. The drinking water problem of the tigers in this Core area has already been discussed. The trouble doesn’t end here. A majority of the Core area lies in the wider part of the sea bank or mouth of the rivers. On the other hand the altitude of these Sunderban islands is not much from the sea-level. Hence, all the oceanic tempests, tidal waves etc. affect this Core area first. Secondly, the rivers from the north have all surrendered to the backwaters even before reaching the sea due to decreased waterflow. Thirdly, the expanse of grasslands in the Core area has hit the bottom due to extreme salinity. Therefore, Spotted Deer (Axis axis), the chief fodder for the tiger, is fast disappearing there. The main question is how much safe is the troubled Core area for the Sunderban tigers? They have to fight food scarcity, unavailability of drinkable water as well as oceanic threats on a daily basis. One should not forget that a huge wave can easily eradicate the entire flora and fauna of the Core area. Thus immediate solution is inevitable. If the Sunderban tigers have to be truly preserved in the face of Nature, then the Buffer area has to be immediately transformed into habitable land for them. It’s true that this might increase straying cases in the adjacent villages but it has to be coped with by all means.

Now let us reflect upon the principal issue. Why the tigers stray-out of Sundarbans and enter villages? I have already mentioned at the beginning of the write-up that in the past 11 years tigers have strayed at least 88 times from the Sunderban Tiger Reserve. They have entered the villages 65 times. The apparent causes for tiger straying in the Sunderban are hereby categorized into four divisions:

  • Customary illogical causes
  • Customary logical causes
  • Scientific causes
  • Observed and verified causes
Attraction towards human scent:

There is apparently no basis for this cause. Though the etymological meaning of tiger (in Bengali) is a creature with strong olfactory sense yet there is a dilemma, after much scientific research and analysis, regarding how many these killers can smell? In spite of enormous breakthrough in the world of zoology, we have to yet trust a lot on guess work and some scattered research papers for such issues. But, on studying the behavioral structure of tigers, it seems at first that they don’t possess much olfactory sense. In this case the cat family (Felids) is far behind the dog family (Canids). But the suspicion lies in, whether these creatures can smell at all or do they utilize their olfactory prowess only in special cases. We often witness a heightened sense of smell among the dogs than their feline sisters. But if we closely observe the cats around us, we would see that their sniffing habit hasn’t turned into an obligation like the dogs. This might also be because of evolutionary reasons. Dogs sniff out of compulsion but cats don’t. There are a couple of domestic cats around my home and I have observed that if there is no fish on the platter they don’t even bother to show up but if you happen to buy some, they would immediately appear at your window-sill, no matter whether the fish is- in the bag or on the plate. How can they sense this if they can’t smell? Or maybe, they have some informer friend from the animal world. No, this isn’t a humorous affair since I have seen a lot of ravens informing their lesser crow friends. But in this case cats have no luck in informers. Hence we can safely infer that cats possess the power of smelling. If the cats can smell, then the tigers must and so do the Lions, hunting Chitahs and Leopards.

But the first trouble was encountered in Jim Corbett’s statement. He said that tigers possess nil sense of smell. Brander claimed that they do but on a very lower level; his pet tiger cub couldn’t smell a piece of meat placed only 7 ft above the ground! Wilmot went a little further and said that tigers can follow an animal on its scent but it cannot figure out a human sitting a few feet above on the ‘machan’. Baagbi recounted his experience in this regard: “I was stationed on a very low machan that time. I saw the tiger smell something unusual and it got extremely restless. It left on not being able to figure out the source.” Sanderson then said “it is very natural for the tiger to feel stunned by human scent”. Ardley Wilmot compared the deer’s inability to sniff out a human sitting on a higher ground. But strange enough, how can they sense a human, far away, when on ground? I had a talk about this about 15 years ago with former Divisional Forest Officer Mr. Ramprasad Dutta. He had the opportunity to work at Sundarbans for 12 years and thereby had gathered a lot of experience. He told me a fact, which is so relevant in this context. Mr.Dutta said, “That year, the responsibility of showing the Departmental Secretary, the king of the Sundarbans, fell on me. Unfortunately the last 12 times the secretary had no luck. This time he wasn’t that hopeful either. Yet arrangements were made nonetheless. A pig was strung on the bank of the water stretch near the Netidhopani watch tower as bait. Strangely the pig fought a lot when it was brought down the boat but it showed dead quiet when tied to the peg near the pond. It remained so for hours together! It turned on its side only once but that too at a lightning speed; there wasn’t any movement of the limbs henceforth, not even an ear flapped. This went on for a couple of hours. Ultimately the tiger ambled into view. It came straight below the tower after crossing the pig in five feet or so. But it didn’t sense the poor creature at all!”

Macloyd offered an even more astonishing fact on this account. According to his experience “A tiger will come to devour his kill from a great distance. But if the carcass is shifted a bit from the original position it was killed, the tiger can no longer find it out!” Ratanlal Brahmachari raised a question in turn: “Can tigers really not find a carcass when shifted? Or is it because of instinctual precaution?” Sarojraj Chowdhury has affirmed to Brahmachari’s logic. He claimed to have seen his pet tigress, Khairi, following the scent of a monkey or a monitor lizard by sniffing the ground. But science can never depend on instincts or witnesses; the truth is revealed from research and experimented results only.
In this case, the first ray of hope was provided by two German zoologists – Schnyder and Lehausen. They showed that every animal of the cat species displayed a certain pose by sticking their tongues out, when they smelled something. This is scientifically termed as “Flehmen”. The tiger is known to portray this habit the most. Therefore the biggest evidence of whether the tiger can smell is the “Flehmen”. This is done by tigers, lions, deer and almost all animals. They not only smell through this but also internalize whatever subtle molecule rises from the scent and judges them though the sixth sense. It works almost like a forensic lab – the scent belongs to which animal, whether it is of the same species, what is it trying to convey through the scent, etc. get registered through this function. This sixth sense plays a crucial role in deciding the coital impulses as well as abstinence too. This super sophisticated sense organ resides at the inner mouth of majority of animals. Several unknown and startling facts on this matter have tumbled out from the researches of scientists, named Jacobson. Hence it is proved that the tiger do possess olfactory sense. It might not be required for hunting purposes, but it is utilized adequately when the tiger is wary. The tiger depends more on its visual and aural senses while hunting. Now if we take a look at the Sunderban scenario, we would see that in the span of 5 years, from 2003-08, the tiger has strayed into the village for more than 20 times. Out of these, only 1 human casualty and 1 human injury has been reported due to tiger attack. Therefore it is completely unacceptable that tigers stray into villages because of human scent.

Scarcity of food in the forest:

There might be a scarcity of food in the changed natural habitat of the Core area of Sunderban. We have already discussed this but it is highly unacceptable that the tigers of the Core area are straying into the far flung villages in search of food! There are two reasons for this. First, there would be tremendous infighting if this happens. It is improbable that the Sunderban tigers are devoid of territorial rivalry. Hence no tiger will accept another one crossing its terrain and in order to come to the villages from the Core area, the tigers will have to cross the Buffer area.  Secondly, there shouldn’t be any dearth of food in the Buffer area! There are around 8000-10000 spotted deer, at least 2000 wild boars and innumerable monkeys in this region. The rate of breeding is also pretty high among these species. Therefore there shouldn’t be any shortage of food for sum 100 tigers in Sundarban due to unavailability of preys unless they want to change their appetite due to evolution. This trend is witnessed in the Kaziranga forest of Assam. There has been a steady rise in the tiger–rhino clashes. Most probably it is because of the tiger’s interest in the rhino cub. It is always easier to kill the little ones of any species. There is no fear of counter attack and the level of fat and cholesterol is also less in their flesh. The tigers of the Sunderban similarly thrive on the infant spotted deer; thereby maintaining the ecological balance. The Parent Stock remains the same more or less. They continue to increase their family and the carnivores seldom fight them in fear of counter attack.

Now let us return to the main premise. Apart from deer and boar, the tigers of Sunderban have a special weakness for monkeys and monitors. However strange it might seem, the tigers of Sunderban do devour a lot of monkeys. I have witnessed this amazing feat one time. Recently one of my friend asked that “how can tigers, which aren’t able to climb, get hold of monkeys residing high on the trees?” I answered, “Tiger is cunning; it consumes honey by breaking the comb. Before doing so the tiger smears a thick coat of mud and dries it in the sun.” There are several such startling stories of a tiger’s skills. Monkeys, like humans, have poor eyesight at night. Therefore the community takes shelter on a tree at night. The tiger creeps up to such a tree and roars tremendously. Stunned, a couple of sleepy monkeys fall off the trees and the tiger snatches one or two for its dinner. Therefore it is unacceptable that the tiger would stray into the villages of Sunderban despite of such abundance of food in the Buffer area.

Problems during childbirth:

There is a customary belief that tigers stray into human locality due to problems during childbirth. It’s true that most of the male members of the mammal detest their offspring. They, at times, mercilessly kill the little ones too. Except reptiles and amphibians this behavior is seldom seen in the female members. This kind of conduct is seen among a few male tigers also but it doesn’t hold true for every male animal. There are many exceptions in the world. This concept has risen from observing animals like tigers and cats. The tigress searches for safer regions, during childbirth, for natural reasons. But it would be wrong to assume that the females search for safer zones only out of fear of their male companions. The pregnant females take precaution because of other predators too. If such is the case, then why will the tigers of Sunderban choose to move to human habitats from the forest? The animal that seldom ventures into the Buffer area will select unfamiliar and chaotic villages when they are pregnant! The most interesting question that arises then is how many of the tigers captured in the villages turned out to be pregnant? An affirmation is highly doubtable!

CUSTOMARY LOGICAL CAUSES: Advanced age and injury:

There is sufficient reason for this belief. We know that the Sunderbans is coated with pneumatophores. Animals without hooves suffer injuries because of this. The tigers’ paws are therefore hurt due to incessant walking on the pneumatophore filled ground. The tigers themselves cure slight injuries by saliva treatment. But majority of times, the wounds are deeper, due to the tigers’ heavy body weight. Hence, they not only take a longer time to heal but start to putrefy too. The tiger becomes inefficient in hunting then; it can no longer risk leaping around the forest in search of food. It then ambushes along the river side in darkness waiting for an easy prey. If it cannot catch one it is compelled to swim across.
On the other hand, most of the Sunderban villages are situated on the fringes of the forests. They are separated only by a narrow stretch of river or inlet. Every village has some cattle that are ritualistic offerings. These creatures don’t find shelter in any house; hence they roam around the village. At night their roaming takes them to the rivers wherefrom they are closely watched by the waiting tiger from the other side. It slowly wades across and strikes suddenly. This way the tiger gets used to easy kills and strays into the villages. There lies the problem, if humans happen to cross their path, they swiftly execute them too. Mostly though, tigers tend to run into kitchens and cowsheds to protect themselves from the humans.

There is another pertinent reason for the tigers to go for easy kills – decay or absence of the canine teeth. The tigers primarily use canine to puncture the arteries of its prey. But in the absence of smaller preys they are forced to kill larger ones, thereby putting greater pressure on the canines. The animals put up a great fight and it becomes more stressful for the solitary killer to suffocate it. Hence the encounter broken or decayed canines and the next chase becomes all the more difficult. Lions, being pack hunters, don’t face this snag.


According to many, the reasons for tiger straying in the Sundarbans, runs deep. Tsunami hit in 2005; assumptions reveal that the tectonic plate movement of the Indian shelf during the Tsunami has increased the salinity level of the Western or Indian Sundarbans. Topping this, the sources of the rivers or sweet water bodies are shifting westwards. Resultantly, the grasslands are altering their positions to the South 24 Parganas, leaving the ambit of the Tiger Reserve. The herbivores are unsurprisingly shifting base too and so are the tigers. Maybe because of this phenomenon, the tigers are straying more in the Western part of the Sunderbans than in the North. The roots of this thought run deep and there is plenty of researchable matter too. But whether the consideration for the tigers would run this deep is the main concern.


Having observed wild animals for years now, it seems that the basis of all behavioral patterns of animals is the same, irrespective of elephants, men or ants. I have been ridiculed wherever I mentioned such realization. Once I asked a friend: “Have you ever been to the mountains?” He said: “Yes”. I asked: “Why?”  He replied: “I enjoy it hence.”  I enquired: “Why do you enjoy?”  This time he was truly perplexed. I assisted “Because of adventure.” My friend then grasped the matter and strongly supported the logic. I then questioned that “if you can like adventure then what is wrong if the tiger likes it too? But of course you wouldn’t want to do it when you are old!” The friend could not comprehend the head or tail of it. The truth is a majority of the young tigers stray into the villages of Sunderban out of pure curiosity. They penetrate the forest adjoining villages like Samshernagar, Kulotoli, Jamespur, Pakhiralay, Rahat Jubilee, Pirkhali, Bali, Dayapur, Mitrabari, Lakhimpur, Glasskhali, Sonagaon, Hetalbari, Satjelia, Kalitala, Amlamati, Hemnagar, Satyanarayanpur, Klaidaspur, Kumirmari, etc. But not all cases of straying out are due to adventure; only a percentage of straying tigers fall under this category.” My friend agreed at last.

Fog Factor:

What connection might the straying of tigers have with fog has surely not crossed the minds of any renowned zoologist or observers like me. But it’s strangely noted that about 40-45% of the tiger strayings in Sunderban happens between the wintry months of November and January. The river and forest is fused together due to dense fog. It’s impossible for one to separate the land from the river. Several people who travel by boats during this time would confirm that all the islands resemble each other from a far. They are surrounded by innumerous trees and shrubs; inhabited islands and forest islands look the same. During night the situation turns grave. We have mentioned before that the tiger has brilliant vision due to the presence of Tapetum Lucidum in its eyes. But this agent most probably doesn’t function well in the fog (like difference between the head light and fog light of a car) and they end up entering the inhabited islands.

There is another crucial issue here-the Territorial Concept of the tigers. It is said, that every tiger or tigress marks its area with the Marking Fluid that is released from the body. This subject is examined in Nepal’s Chitowan and a few other places in the world. An average calculation is in vogue too. Male tigers mark about 50-1000 sq. km. of area as their territory whereas the females mark one-third of this. Its hard to accept this since a question about how does a tiger finds its way back into the village from the island it was deserted at arises. But there is a counter argument to this-there isn’t any Territorial factor among the tigers of Sundarban! Sometimes its said that about three tigresses dwell simultaneously in the territory of a single male; albeit separately. Its only during breeding season that the tiger copulates with the menstrual tigress; and each time its separately. A tiger is never accompanied by two tigresses at the same time; mother and adolescent cubs are an exception.

Factually one has to accept that all animals, Tiger, Cow or Goat, has this Territorial Concept. It all depends upon the environmental circumstances like uninterrupted resting place, abundance in food and suitable companion. This holds true for everybody. But when the basic needs of life are unavailable then all concepts seem meaningless; consider the situation during 1971’s Famine in India. Copious number of people used to flock the cities in search of a morsel of food, run after helicopters for the limited amount of food stacks notwithstanding where those stacks fell. This is one fragment; men fight for an ounce of shelter, refugees scourge for a roof above their heads. The lover overcomes every hurdle to be united with his mistress. If this be the tale of human desires, then what wrong can the beasts do in chasing theirs?

The basic requirements are the same for everyone; tigers are no exception. They will inevitably roam around in search of food, shelter and companion. Though they try to avoid each other during the rest of the year but miserably fail to do so in the foggy winters and land up on each others’ territories. Thus begin tremendous Infighting. The defeated tiger beats a hasty retreat and jumps into the water. Before it can comprehend to which side of the river it has swum across, it is shoved around by hundreds of men, driving teams, nets, rifles or is beaten up mercilessly! If rescued, the tiger is saved, else there ends the life of the predator.

The reason for this detailed discussion is, because, we consider the fog to be the chief culprit behind Infighting in winters. The other round the year reasons are already discussed. However this new cause (Fog factor) of tiger straying was accidentally and first noticed by me. Immediately I collected the stipulated days’ (the number of days in the last three winters when the tiger strayed into the villages, fog data from the Canning Station, it being the nearest observatory of the Weather Department in Sundarban.

To speak the truth I couldn’t believe that I was capable of making a discovery. My anticipation proved to be correct- astonishingly 82% of the days in the last three winters, when the tigers came out of the forests, were reported to be densely fogged. I arrived at the same inference after observing my pet cat. I had started a deeper observation too.

Lastly I think, that considering the precarious condition of the fringe villagers of the Sundarbans, immediate measures should be taken to stop the tigers from entering the villages. Simultaneously, this royal creature of the Nature has to be preserved too. I can vouch that the task is not impossible.

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