Road to nowhere: reconnecting India’s fragmented tiger reserves

Over the last decade or so, numerous accounts have emerged from India to illustrate the perilous state of its endangered tiger populations. Perhaps the most high profile of these surrounded the extirpation of tigers from the Sariska reserve in Rajasthan in 2004, an event that proved to be the catalyst for a fundamental review of conservation policy in India. The most poignant story I have heard from this period, however, emerged via Prerna Singh Bindra in her book ‘The King and I’. Reporting from one of the lesser known reserves, Palamau in the state of Jharkand, Bindra recounted the sad tale of Rani, a six year old tigress. She was the last remaining member of her species to inhabit the park and she continued to patrol her territory, issuing a series of plaintive calls to attract a suitable mate that no longer existed, oblivious to the futility of her situation. Reality dictated that Rani was doomed to live out the rest of her life in isolation, the last of her kind. The reason behind her enforced solitude was not difficult to comprehend as Palamau had become a virtual island, its connectivity with outlying habitat blocked by a combination of human encroachment and development. The despondency of this tale is compounded by the inescapable fact that such episodes are likely to increase in the future as the permeability of tiger reserves becomes further compromised. And, once critical dispersal corridors are lost, they are notoriously difficult to recreate.

A lone Bengal Tiger on a road
Tigers use roads for patrolling in territories. Image by Suzanne York

David Quammen offers an interesting analogy in this regard, likening the habitat matrix to that of a Persian carpet. In its entirety, the pattern of the carpet is clear, flowing seamlessly across its surface. Imagine though, taking a knife to the carpet and slicing it into a series of smaller squares. The pattern is now disrupted, each edge of each fragment fraying and unravelling further over time, the gaps between becoming more pronounced. Even the most experienced of restorers is unlikely to be able to replicate the original pattern, to fuse the frayed threads back into a semblance of its former connectedness. This is the same for a tiger landscape and, to add a further dimension, the area of decline in each of the remaining habitat fragments becomes subject to an increasing edge effect. In order to explain this phenomenon, let us return to the example of the carpet. Say, in its original state, the carpet measures 10 metres on each of its four sides. This gives us a total edge of 40 metres. It is this area that is more prone to deterioration than any other portion of our carpet and we can see from a quick glance that it has been strengthened by an extra layer of stitching to prevent it from scuffing and fraying. Now, say we cut the carpet into one metre squares and lay these individual fragments side by side in an approximation of the original design. Now, the edges of our individual remnants add up to 400 metres, a ten-fold increase. When the metre-square fragments are initially laid side by side they may fit closely together with only small fissures between, but as the cumulative effects of foot traffic act upon the fabric over time, so the individual edges are revealed and erode at a faster rate. Returning to the core issue of our eroded tiger reserves, this process of fragmentation leaves the remaining habitat patches prone to increased human encroachment and industrial infiltration, accelerating the rate of decline. What were once uninterrupted habitats harbouring healthy tiger populations become a series of disconnected islands as, as we have seen in the previous post, this leaves resident tigers increasingly susceptible to the pernicious effects of inbreeding depression.

The previous article entitled ‘Cat of 9 Tails’ focused on the thorny issue of taxonomic inflation, recognising that the subspecies approach may have inadvertently contributed to a depletion in genetic diversity across the tiger’s geographical range. Today, in India, it is claimed that tigers now occupy a mere seven percent of their historical habitat and that over 90 percent of their number are restricted within the country’s network of protected reserves in at least 76 discrete groups. Two recent studies published in the ‘Proceedings of the Royal Society B’ in 2013 suggest that, in India at least, this has occurred as a result of an ongoing decline in connectivity between increasingly isolated units of tiger habitat.

tiger and felled tree
Deforestation in and around tiger reserves destroys habitat and fragments dispersal corridors. Image by Christopher Wong.

Loss of habitat has long been viewed as a major obstacle to effective tiger conservation but it is arguably its fragmentation that has exacted the greatest toll on the big cats. A fundamental understanding of tiger culture and behaviour reveals how the blocking of key dispersal routes has led to insularity in modern day tiger populations, an issue that may have dire repercussions for the long-term persistence of the species. In the first paper, researchers studied historical levels of mitochondrial DNA found in tigers that had been hunted during the period of the British Raj, now contained in museums, and compared the data against those of their modern day descendants. Their findings suggested that, over the intervening period, genetic heterogeneity had declined and that only 93 percent of historical DNA variants remained.

Michael Bruford, one of paper’s co-authors, emphasised the link between this loss of diversity and the partitioning of tigers in small pockets of protection that have lost connectivity to outlying forests. “This will not go away until wild places are managed coherently” he argued, adding that the Indian authorities needed to rethink the way in which it measured conservation success, rather than continue to restrict its focus on tiger numbers alone. The second paper picked up on this theme, focusing on tigers inhabiting different zones of the Satpura – Maikal landscape of central India, investigating their genetic make-up to ascertain the extent to which corridors were functional or not. Their results pointed categorically towards the fact that the highest rate of gene flow coincided with sites displaying the greatest habitat connectivity. This, the authors argued, had major implications for conservation policy and practice, consistent with an emphasis on landscape-level protection measures. Here, the broader theme of source-sink dynamics needs to be considered.

Source populations describe those tigers occupying prime habitat in the core areas of inviolate reserves, utilising the available space to establish their territories in prey-rich, protected landscapes suitable for breeding. As their numbers grow, older tigers can become displaced through territorial contest and, as they mature, sub-adults are forced to disperse in order to establish their own territories. In each case, areas on the periphery of reserves act as transit routes, and to be effective, need to connect other source areas to maximise the potential for genetic exchange. The areas between these source locations are known as sinks and these zones contain transient tigers seeking to disperse. They can therefore be seen as sites of potential conflict as tigers come into contact with humans communities living in close proximity to the reserves. It is within these buffer areas through which transient tigers pass, and sometimes settle, that are referred to as sinks. Here, the habitat is less secure and subject to enhanced levels of human presence and associated development pressure. It is also these areas that have become an arena in which a variety of human-tiger conflicts are played out, particularly in those spaces where critical corridors have been disrupted, effectively trapping tigers within human-dominated environments. Remedial activity within these sinks is therefore viewed as a prerequisite in the broader battle for tiger survival.

A tiger crossing a forest road in Pench Tiger Reserve.
A tiger crossing a forest road in Pench Tiger Reserve.

Action to rehabilitate sink areas has tended to play a secondary role to the protection of source populations. This focus on the core areas of tiger reserves is of vital importance as, without successful breeding, movement beyond protected area boundaries remains limited. However, given the reported resurgence in tiger numbers reported in the All-India Tiger Estimation of 2014, the stocking density of certain tiger reserves is rapidly approaching saturation. In this case, the presence of transient tigers seeking to disperse is generating increasing pressure in the sinks. The task of rehabilitating these passages, however complex it may be, is therefore of vital importance to any landscape-level conservation approach. Rigid adherence to the conservation of source populations is no longer a viable proposition and it can be argued that forest officials are currently doing just half the job and that action in the sinks is now imperative. As intimated above, though, this is far from a simple task. There are major hurdles involved in the re-establishment of an appropriately linked-up landscape matrix in sink areas.

stone mine in a tiger reserve
It is not just construction that constitutes a threat to connectivity, but also mining for the minerals to enable it – Sariska Tiger Reserve

These buffer zones are designed to be multiple use in nature and contain human settlements and the supportive infrastructure required to survive in what are perceived to be hostile environments. Marginalised local communities often rely on the availability of firewood to meet their energy needs, also utilising the space to rear and graze their livestock. Here, cattle and goats compete with tiger prey for resources and, in the absence of sufficient prey, domestic livestock becomes an alternative food source for tigers, heightening the potential for conflict.

The future of these sinks remains under pressure for development and, just as its difficult to turn back the clock, it is virtually impossible to hold back time. Recent reviews of india’s inability to sustain its economic growth rate have identified the relative paucity of infrastructure as a determining factor in its failure to match China’s meteoric rise as a global economic powerhouse. This understanding will inevitably contribute to more pressure for infrastructure in and around tiger reserves, evidenced by recent developments in the Kanha-Pench landscape, subject to the construction of National Highways 6 and 7. Effective planning is crucial to such developments and, in an effort to reduce their impacts on endangered wildlife, the introduction of a smart green infrastructure (SGI) approach is essential. SGI is a planning mechanism and is based on the identification of a hierarchy of mitigation responses, consisting of four distinct options: avoidance, minimisation, restoration and offset. These categories reflect the extent to which any proposed infrastructure is required and provides planners with a series of options in countering the associated decline in habitat connectivity as a consequence of development. Roads are undoubtedly a threat to tiger dispersal.

dead tiger on National Highway 212 Bandipur
Tigers are rarely killed on roads, but roadkill incidents are not unknown – National Highway 212 Bandipur 2003

While road kill incidents remain comparatively rare, highways nevertheless create a major barrier to tiger mobility and can fracture historical dispersal corridors. Proponents of SGI claim, however, that new developments of this kind may also provide an opportunity to enhance connectivity, while opponents view it as just another justification for development to take place in vulnerable natural venues.

Let us now consider some of the benefits that may accrue from the adoption of the SGI process. Firstly, it embeds wildlife concerns into the planning process and creates a situation, in theory at least, where applications may be refused, or roads re-routed, if they are deemed to be detrimental to conservation objectives. Secondly, if such developments do receive a green light, which they inevitably will in most cases, then the SGI process demands that minimisation of resulting disruption must be considered and acted upon. This is perhaps more feasible than the avoidance option. Restricting our focus to the construction of roads it is useful at this point to consider one potential scenario. In places where transport networks intersect with key migration routes, it is possible to construct underpasses or to raise the level of roads to enable the safe passage of wildlife. Where potential accident hotspots can be identified, these can be fenced off in order to channel animals towards safer crossing points where strict, enforceable speed regulations can be imposed. This could be supported by the fitting of CCTV technology to monitor not just speed transgressions but as an early warning system to the presence of suspected poachers. In recognition of the expanded edge effect that such developments create, the issue of compensatory and offset investments can be used not only to fund increased patrols in vulnerable areas but also to provide services to local communities. This is vital in areas where human-tiger conflicts are deeply entrenched and may prove to be a way in which to reduce the incidence of such conflict and build support for wildlife within these marginalised communities.

At present it is unclear how successful SGI will prove to be in protecting vulnerable tiger corridors. Indeed, in India, it remains far from certain that it will even be adopted as a central component of the planning process. What is clear, however, is that in the absence of remedial action in sink areas, tiger landscapes are likely to lose their connectivity altogether.

A traffic jam through a tiger reserve
Bandipur Tiger Reserve – Heavy through traffic threatens tiger dispersal

Today, these areas are subject to no legal protection and concern is thus mounting that the fabric of tiger habitats will become increasingly frayed, unravelling at a greater pace over time as development opportunities are taken up. Without action being taken to reverse this trend, there are two outcomes that are likely to emerge. First, emphasis on the exclusive protection of source sites may culminate in tigers existing as boutique populations, requiring enhanced levels of human intervention to effect the levels of genetic exchange sufficient to perpetuate the species over the long-term. The resulting tiger groups may become, to all intents and purposes, captive, existing merely for show to the hordes of tourists descending on the remaining showcase parks. Second, the tiger may be abandoned to its own devices, left to slowly succumb to the injurious effects of inbreeding depression. Here, we may be creating more Ranis, isolated tigers forced to wander aimlessly down roads that lead nowhere, waiting impotently for the demise of their species. Neither scenario provides much hope for the future of the tiger in the wild, so it is vital that we act now to protect and, where needed, restore our carpet, to reconnect all of its fibres to make it as complete as possible, before decay becomes irreversible and the tiger becomes lost to the wild forever.

 

 

Cat of nine tails – is the preoccupation with taxonomy compromising effective tiger conservation?

They say that a cat has nine lives but does it also have nine subspecies? This is a debate that has reopened recently in response to a paper published in the journal ‘Science Advances’ in which the authors claimed that, in reality, there may be only two extant subspecies. What does it matter? Well, claim the authors of the latest study, the current emphasis on taxonomy may be harming the practical application of effective conservation strategies across the tiger’s geographical range. It may be restricting opportunities to reinvigorate genetically-depleted populations and to develop and employ integrated strategies in efforts to ensure the long-term persistence of the species in the wild. More money is spent on the protection of tigers than for any other species, reflecting the global popularity of the largest of the big cats. But how effectively is this money being invested? At present, clinging to what may be an outdated understanding of genetic heterogeneity fragments the employment of such capital in responding to modern day realities affecting tiger protection. Before investigating this issue further it is first essential to understand the how and why of such taxonomic classification.

Tiger subspecies of the world: bengal, Indochinese, Malayan, Siberian, Sumatran, South China,  Javan, Caspian, Balinese
A graphic illustration of conventional sub-species classification by Jenny Parks.

The concept of the subspecies is a way in which to recognise variability within a species, both in terms of its geographical distribution and its morphology. Not all geographical differences are deemed sufficient, however, for such a taxonomic departure as these may be viewed as being clinal in nature, or to put it simply, gradual changes to certain characteristics exhibited by adjacent populations of the same species. So, while geographical distance may be an indicator of taxonomic differentiation, it is not necessarily sufficient. Why? Well, tigers are a mobile species. They move around, they shift to other territories to enrich the genetic make-up. At least they do if the dispersal routes are free from obstruction, which sadly today few are. For this reason, scientists have estimated the maximum dispersal distance of tigers as being up to 1,000 kilometres. Tigers are, therefore recognised as a highly adaptable species and their historical range encompasses a variety of different habitat types. From the frozen taiga landscapes of the Russian far-east to the steaming jungles of the Indonesian islands, tigers have colonised a surprising number of ecotypes.

As these areas differ so much in terms of their physical and climatic structure, so tigers have developed traits to ensure success in their various homelands. The northern tigers, having to endure the sub-zero, snowy conditions of the higher latitudes, have assumed larger bodies, carrying more fat to insulate them from the severe winters. Their coats tend to be longer, their colour (or pelage) a paler tint and their stripe patterns wider apart than their southern counterparts. In contrast, the smaller, slighter Sumatran tigers are brighter in colour with their stripes set closer together, similar to the now extinct Balinese and Javan varieties. In terms of the other extant subspecies, similarities are so close that differentiation remains a difficult task. Similarly, some variation in morphological features, such as cranial size, do occur, but once more it is difficult to attribute this to the emergence of a subspecies. Indeed, critics of the resulting taxonomic classifications argue that the underlying science may be flawed due to the use of small data sets and, in some cases these date back over a hundred years. Hence, the whole foundation of the subspecies approach is open to question, with the authors of the latest study arguing that, instead of recognising nine subspecies this should be reduced to just two; the northern (mainland Asia) and southern (Sumatran) groups.

As science and technology continue to develop at a rapid pace, so too do the tools available to researchers and, recently, genetic studies have provided conservation with fresh insights as to the state and structure of the world’s remaining tiger populations. What has emerged from the resulting literature has been a recognition that the tiger is perhaps the least diverse of the big cats and that, genetically, there is an urgent need to replenish gene pools within its beleaguered numbers. This, it can be argued, is in direct contradiction of the taxonomic restrictions imposed by a proliferation of subspecies, described as ‘taxonomic inflation’. Part of this limited genetic base can be attributed to historical events which have led to a series of demographic contractions over time, reducing the breeding stock available to propagate the species. This situation has left tigers susceptible to the effects of inbreeding depression and, today, only an estimated 1,000 females remain to repopulate a diminishing range.

This situation has undoubted ramifications for the future of tiger conservation. It is perhaps inconceivable that the plight of the tiger will improve dramatically over the coming decades. Indeed, it is far more likely that, as human populations and economies expand even further in the foreseeable future, so too will threats to this charismatic species. The good news (albeit contentious) radiating from the recent tiger population estimations in both India and Russia, needs to be read with caution, not least in terms of apparently expanding numbers offset by a diminished habitat range. It is hard to escape the fact that the tiger is a conservation-dependent species and one that will struggle to survive without human intervention. Moving forward, it is likely that this required intervention will become increasingly pervasive and driven by scientific innovation. This may involve a range of reintroduction and relocation initiatives, perhaps ultimately from captive bred specimens. In this case, blind adherence to the notion of taxonomic purity may restrict rather than facilitate efforts to rejuvenate diversity in tiger populations, an unintended consequence of which may be its ultimate extinction in the wild.

To illustrate this concern, a recent report in the Washington Post has likened the situation to that affecting another big cat, the Florida panther.

Florida Panther on log.
The Florida Panther – Rebounding from near extinction

During the early 1990s, it was becoming increasingly clear that the writing was on the wall for this species. Its numbers had declined alarmingly due to a combination of habitat degradation, development and human intolerance and, with less than 30 individuals remaining, its remaining population was insufficient to ensure its persistence in the wild. It had entered a genetic bottleneck that was difficult, if not impossible to reverse. It was accepted that, without radical remedial action, the Florida panther was likely to be relegated to the status of a ‘relic’ species, which in the words of Professor Stephen Meyer from MIT, are forced to occupy “the margins in ever-decreasing numbers and spatial distribution” before descending further to become ‘ghost’ species whose extinction is inevitable. Heavily blighted by inbreeding depression and its accompanying genetic defects, time was clearly running out and, in a last-ditch effort to save the Florida panther, the difficult decision was taken to introduce eight female Texas cougars to rejuvenate the gene pool.

But how difficult was the decision in reality? The truth remained that the Florida panther and the Texas cougar were very closely related and the decision came down to one key question. Do we simply let the Florida panther disappear or do we instead relax the taxonomic idealism and make the more pragmatic choice to intervene?

Close up image of a Texas Cougar
The Texas Cougar – Providing the required genetic inputs to ensure the persistence of the Florida Panther

Unsurprisingly, pragmatism prevailed and, today, the panther (albeit with a little help from its friends) has rebounded to somewhere between 100-180 individuals. Whilst their future remains far from assured they have at least enjoyed a stay of execution from the permanence of extinction. This story has evident parallels with that of the tiger. The question, across Asia, is startlingly similar. Do we accept some degree of genetic pollution or do we instead cling valiantly to a naive belief in genetic purity at the expense of the species as a whole, based on what increasingly appears to be a flimsy base of evidence? To answer this question more fully, it is useful at this juncture to return briefly to the turnaround in the tiger’s fortunes in India. As discussed in my previous post, despite the controversy surrounding the operation of the latest All-India tiger estimation, tiger numbers are generally regarded to be on an upward trajectory. This apparent growth, however, appears to be occurring primarily in a series of strictly demarcated parks reserved for tiger conservation, while outside their boundaries increasing levels of human activity are having a detrimental effect of blocking dispersal routes, restricting their movement and compromising their ability to colonise new territories. Opportunities for tigers from adjacent communities to meet and replenish the gene pool are therefore increasingly difficult to facilitate. As with earlier demographic disruptions, leading to the identification of taxonomic departures, this situation depletes isolated communities of their diversity, increasing the risk of future extinction episodes. This becomes ever more likely as poaching crises emerge and indeed, during an era of increasing climate change, where conditions are likely to exert a fresh set of pressures and challenges on the big cat.

Returning to the ‘Science Advances’ paper, lead author Andreas Wilting claims that previous efforts to curtail taxonomic inflation in the case of tigers have largely failed to gain traction due to a lack of evidence in support of its reversal. As we know, research can move slowly, one small advance at a time. Even where research finally emerges to suggest a rethink in policy, this process can also be pedestrian. Wilting, however, believes that the evidence now exists and that it translates into a strong message for the conservation community to act now to better organise tiger conservation globally. Other critics support this stance and question the trend towards identifying species in terms of their ancestry, an issue largely ignored in this particular post, rather than through their current, physical traits. After all, following such a long period of contraction and repopulation it has become impossible today to understand the linkages between lineage and behaviour, making any discussion largely academic to the needs of the modern tiger. Still others emphasise the influence of technology that has enabled scientists to study wildlife at a molecular level, identifying minute differences in their morphology before translating this information into new taxonomic understandings. Wilting continues by arguing that this process provides “so many species concepts” that you could make a legitimate case to “distinguish each population separately”. Legitimate, perhaps but helpful, definitely not.

Panthera Tigris - How Helpful is taxonomic subdivision?
Panthera Tigris – How helpful is taxonomic subdivision?

Why, then, is it so important to tiger conservation to abandon such restrictive categorisations? Well, the argument proceeds, a strict taxonomic approach brings with it a proliferation of management units, areas in which only prescribed genetical material can be added to the existing gene bank. As we have seen earlier, the current dearth of diversity within mainland Asian tiger populations at least, negates such a need in practice and, with many isolated communities rapidly nearing a bottleneck, only two real options remain. One is to reconnect currently isolated populations through a series of corridors to facilitate greater dispersal between remote, insular communities. This is the focus of my next post and, as we will see, this is particularly difficult to achieve in areas containing large human populations and their associated development and infrastructural support. Secondly, and perhaps more realistic over the shorter term, is the artificial injection of genetic material to challenge current uniformity. This may be based on relocation of tigers between communities and, indeed, within his recent announcement of a 30 percent increase in tigers in India over the past four years, the minister in charge of environment and forests proudly stated that India may soon be in the position to donate surplus tigers to other range states to help repopulate and regenerate their own declining tiger communities. To enable this to happen in the future, a relaxation of taxonomic diktat is vital. Finally, the artificial introduction of diversity may include elements of artificial insemination from captive bred sources and even, in the event that reintroduction methods are developed that enable captive-bred tigers to survive in the wild, the prospect of the repopulation of ranges following extinction episodes may become an increasingly attractive and indeed feasible option.

It will be interesting here to follow the success, or otherwise, of the ‘Save China’s Tigers’ initiative, in which two zoo bred tiger cubs were initially transported to South Africa in October, 2003 to prepare them for ultimate release into the wild in China.

a recently introduced china tiger with it's Blesbuck prey
Save China’s tigers – Tiger training in South Africa represents a radical departure from convention.

The brainchild of London-based Chinese businesswoman Li Quan, two tiger cubs were initially released into the veldt landscape and, following further introductions and subsequent births, the stock of tigers currently stands at eighteen individuals. Contained within a fenced reserve to prevent ingress into the wild, these tigers learn to hunt and the project is described as a ‘rewilding’ programme. The ultimate aim of the exercise is to return the tigers to China following the necessary rehabilitation of appropriate habitat, enabling the repopulation of de-tigered environments. The project is of particular interest as it focuses on the South China tiger, one of the subspecies that is presumed to be functionally extinct in the wild and, indeed the stem species from which the other subspecies are thought to have radiated. It has proved to be a controversial programme to date but, as critics of the existing restrictive approach argue, the whole issue of tiger conservation remains contentious and disputed. But, as we have seen, in order to safeguard the tiger’s long-term persistence in the forests of Asia, tough decisions need to be made and these may be most effective if past regimes are investigated and adapted to reflect modern realities.

The genetic purity versus pollution debate must therefore be debated more fully, as the present focus on subspecies may be leading us down a path of no return – irreversible extinction. Perhaps it is time to discuss ways of more effectively replenishing the gene pools of endangered tiger populations and, whilst remaining vigilant that we don’t compromise diversity, allowing genetic refreshment from outside to boost the resilience of the species to persist in the future. The question is clear. How do we want to see our tigers in the future: in captivity or in the wild? While the answer for most of us veers unerringly towards the latter, how we achieve this is far less clear cut. What is evident, however, is that moving forward we may be forced to intervene more fully in our conservation endeavours and become a little less idealistic in the way we respond to the spectre of extinction. The clock is ticking.

Lies, damned lies and statistics: getting to grips with the all-India tiger estimation controversy

Imagine running a business in which you are totally unaware how much stock you have. This is the situation that faces those that manage India’s national tiger estate. Tigers, as a species, are notoriously difficult to see. They are solitary, secretive animals that wherever possible seek to avoid contact with humans. On my first visit to a tiger reserve I became only too aware of this fact as I returned from successive drives empty handed. When I say empty handed I don’t necessarily mean that my trip was a disaster as I was lucky enough to witness a range of species populating the dry forests of Central India, each a key source of tiger prey but, unfortunately the big prize eluded me. On returning to the lodge I spoke in depth to my hosts who assured me that the largest of the big cats was active across the route I’d been driven and, on day two, I was rewarded not with an actual tiger sighting but with a close-up view of a very large, very real pug-mark that had been left upon the dusty road we were travelling.

Sign at the exit of Bandhagarvh National Park " Perhaps you may not have seen me, but please don't be disappointed. I have seen you."
Although difficult to see, tigers are nevertheless present.

Its very size hinted at the scale and power of the animal that had left it and, just around the next corner a sign post comforted me over my lack of an actual sighting. Here, a cartoon tiger stared down at me, a speech balloon coming from its mouth, informing me that although ‘you may not have seen me, please don’t feel disappointed. I have seen you’.

When I arrived back at base that evening and was flicking through a local journal in the small library I read that, on average, only one trip in 14 actually resulted in a tiger sighting. Clearly, these are not the easiest animals to spot. So, consequently, they are also very difficult to count. The results of the latest All- India Tiger Estimation were announced in January of this year and received enthusiastically by those willing the tiger to rebound from the threat of extinction. As Union Minister for Environment and Forests, Prakash Javadekar revealed the long anticipated result of the 2014 estimation exercise, the response to his words were mixed. Euphoria in some quarters was balanced by incredulity in others. While tiger lovers celebrated the meteoric rise in numbers, experts were more cautious and, as the days passed, their concern grew as to the validity of what they had been told. New analyses soon appeared in the media to challenge the government’s figures and there emerged a view that the new Modi government may have been merely fuelling the feel good factor that had heralded their landslide victory of 2014. If not, then the plight of the tiger had improved to such an extent that the problem was now less one of will the tiger survive than one of how many more can our tiger reserves accommodate before saturation?

Well, the history of the tiger count has been long and controversial. It was following such estimates in the late 1960s and early 1970s that Project Tiger was conceived, in recognition of an alarming drop in tiger numbers that had bypassed most people. Suddenly, a creature that had always been considered ubiquitous in Indian forests was now becoming increasingly rare and, it was considered, that without remedial action, the tiger would soon enter the shadowlands of extinction. Enter the most powerful person in India, Prime Minister Indira Gandhi who, with the backing of global conservation NGOs, considered ways to better protect the Indian tiger. The result of this collaboration was the enactment of legislation (the Wildlife Protection Act, 1972) and the establishment of nine tiger reserves as a safe haven for the country’s remaining tigers, estimated to have fallen to around 2,400 individuals. The reserves were largely carved out of existing protected areas and, within their boundaries, management was to focus on the protection of the largest of the big cats. Over the years, the national estate of tiger reserves has risen exponentially and, today, they number 48 individual sites. While arguments persist as to the success of this approach, the tiger has nevertheless evaded extinction although its numbers have oscillated due to a range of external pressures. Left undisturbed, tigers are known to be a resilient and fecund species yet habitat fragmentation has proved to be an ongoing problem as has the depletion of prey species, much of which has been for the consumption of impoverished local communities.

Then, in the late 1980s and into the 1990s, the first signs of a poaching epidemic materialised and once again, Indian tiger numbers declined. Since then, every effort to count them have added to the argument as to the best way to estimate their numbers. The pug-mark method emerged as the early favourite, where plaster casts of the footprints of tigers were collected, analysed and individual incidences recorded.

tiger pugmark in the dust
Initial efforts to count tigers utilised the now discredited pug mark count approach.

While the figures generated emphasised the continuing success of Project Tiger, It soon emerged that there was a political angle to the registration of numbers as the more tigers a reserve (and indeed the state within which the reserves were located) claimed, the more money provided by the government for their upkeep. Inflation of figures was widespread and experts were reduced to a guessing game of how many tigers remained. All anyone seemed to agree on was that the actual number inhabiting the reserves was far less than the official fiction suggested.

Arguments persisted into the 21st century, with critics of the status quo pointing to the availability of new technologies and statistical procedures available to wildlife managers in more accurately predicting tiger population numbers. It largely remained a talking shop, however, as by 2004 tiger numbers were reported to have exceeded 4,000 individuals. Few believed such hype yet the government clung on to the outmoded pug-mark approach, refusing to accept criticisms as to its efficacy. Then, in 2005 the Wildlife Institute of India revealed that, contrary to census returns suggesting a healthy population of tigers inhabiting the popular Sariska Reserve in Rajasthan, there was in fact no evidence at all to support the presence of any tigers whatsoever. The resulting crisis, and its recriminations, proved to be a landmark event in the management of tigers in India. The extirpation of the big cats from such a high profile reserve prompted a review of the whole national approach towards tiger conservation, including the ways in which tiger numbers were calculated. Finally, the controversial pug-mark count mechanism was being dismantled in favour of a more statistically robust index-calibration approach, utilising technological advances to more accurately predict the extent of, and trends in, the population of wild tigers in India.

Surely this advance was widely applauded across the conservation lobby? Not necessarily, as it soon emerged that while critics welcomed the departure from an outmoded and discredited counting technique, they feared that it had been replaced by an equally problematic approach. Prominent tiger expert K. Ullas Karanth argued that the new procedure adopted by government was based on nothing more than an obsolete statistical technique that had fallen from favour as long ago as the 1930s. Whatever the reality of the situation, this method has now been utilised within the last three All-India tiger estimation exercises in 2006, 2010 and 2014.

As the first results emerged from the 2006 estimation, it became evident that the extent of tiger declines across India had become critical. Based on a median of an upper estimate of 1,657 and a lower figure if 1,165 tigers, the most likely population size was stated as 1,411. The news was greeted with widespread despondency as the world’s media picked up the story, although the figure generated at least appeared to be more realistic than those that had been provided from previous counts. The Indian establishment, stung by what they viewed as a censure of their (mis)management of the national tiger estate, sought to engage more closely with experts outside their familiar networks in order to tackle the shortcomings that had contributed to such a decline. By 2010, the next estimation period, their efforts had seemingly been justified as a headline figure of 1,706 tigers was communicated to an expectant media. This, we were told, represented an increase of 16 percent. Tigers were clearly rebounding, the message suggested, India was finally back on track. But was it? Just as the 2006 estimation was based on a median figure, so too was its 2010 version. This time, the lower limit was 1,571 against a ceiling figure of 1,875.

Following a brief period of reflection, and not a little back patting from those in power, critics pored over the data and came up with a more measured reading of the trends. What if, they said, you consider the figures from a slightly different perspective, say the maximum number from 2006 against the minimum range for 2010? Say, for the sake of argument that these were indeed nearest to reality and what you find is the possible loss of a further 86 tigers in just four years. Hardly something to celebrate. Add to this the fact that the 2010 count included areas not employed in the 2006 estimation, a prime example being the Sunderbans which yielded a further 70 estimated individuals and, far from rebounding, tigers may well be continuing to decline. An even closer look into the data reveals that the reported rise in tiger numbers had occurred during a period of accelerating habitat loss and, taking the published figures at face value means that the 16 percent rise in tiger numbers was achieved across a national estate that had lost 22 percent of its territory. This implies that tiger densities in India had increased by a staggering, and less than realistic, 49 percent in just four years.

Graph showing a constant rise since 2006 using the new counting approach
The headline data for the 2014 tiger count was eagerly picked up by the world media.

Let us now move on another four years and consider a little more closely the latest All-India tiger estimation results released in January 2015. The official estimate was revealed to be 2,226 (representing a 30 percent increase in numbers) based upon a minimum limit of 1,945 and an upper range of 2,491. Whilst the previous assessment was restricted to tigers inhabiting protected areas, the 2014 version sought to expand its reach to include all available tiger habitat across the country. The value of this type of exercise, however, is its longevity in providing data over an elongated period that can be compared over time to identify key trends and patterns emerging and to use this management information to better guide policy and action. Constantly changing its terms of reference negates much of its value and, in an expensive process like the tiger estimation, this represents a lost opportunity in the fight to save the tiger.

If the 2010 count had been greeted with a certain amount of derision and disbelief, this time the response was far more incredulous and antagonistic. Karanth referred to the estimation as ‘ridiculous and unscientific’ and, with colleagues set out to discredit the validity of the index-calibration approach in a paper published in ‘Methods in Ecology and Evolution’. Now comes the difficult part. The arguments put forward in this debate are based on complex mathematical and statistical applications, issues of which I have little grasp of. For reasons of necessity, as well as choice, I have therefore attempted to simplify the argument to a basic description of the index-calibration method and the ways in which the protagonists deviate in terms of assessing its value and accuracy. As a technique, index-calibration relies on the measurement of animals over a relatively small territory using a range of methods including camera trap technology.

night vision shot of a tiger face on.
Caught in a trap. Camera trap technology adopted as part of the all-India tiger estimation toolbox

The accumulated data from this stage is then related to more easily available indicators, such as animal track counts by means of calibration. The resulting index can then be used in order to extrapolate numbers over an extended area, in this case the whole of India.

Returning to the study, it goes on to argue that the adopted approach represents a poor way in which to predict actual tiger numbers, and that more advanced, applicable methodologies exist. The subtext here is important as, it appears to me, the crux of the argument is that the Indian government, by clinging on to control every facet of tiger conservation, are missing a key opportunity by their refusal to engage with the wealth of experience and expertise that exists within the non-government sectors. Indeed, a cursory reading reveals the fact that the authors of the article are not even disputing the fact that tiger communities may have rebounded in India, but rather the extent of the rise. Moreover, it points out that management information is only of use if it is accurate and trustworthy. Rather than engaging in a reasoned discussion to justify their stance, the government however have embarked instead on a crusade to force their detractors to retract their criticisms of the generated numbers. This has created an impasse in which both sides are firmly entrenched, compromising the opportunity for informed debate in order to agree on the best way ahead. Here, the prospect of wider partnerships in the immediate future appear at best unlikely.

An image of a tiger with digital mesh superimposed and a closeup showing the stripe pattern
tiger stripes are unique and software now exists to distinguish between individuals

As Lisa Newton noted in her 2005 book on ‘Business ethics and the natural environment’ the resulting lack of meaningful engagement tends to result in the “polarisation of the people best qualified to solve environmental problems” of this kind. Unless such a impasse can be bridged and as long as the protagonists rely, in the immortal words of Mark Twain, on ‘lies, damned lies and statistics’ to justify their divergent positions, business as usual will ensure that, in a little under four years, we will again be revisiting the same arguments. Nothing will have changed.