One of the problems is that in a country as vast as India, with the tiger population scattered throughout its length and breadth, achieving an accurate count is not easy. The field directors of the 23 tiger reserves support the pug mark method in which tiger prints are noted and measured as the most reliable and cost effective way of counting. However, the pug mark technique has not been standardized.
Though identification of tigers through the pug mark has been in operation for ages, there is lack of uniformity in application and even in understanding of the process and procedure, says Dr M K Ranjitsinh, Tiger Conservation Programme Director for WWF, the international conservation organization. Owing to lack of training among field staff, sometimes the left footprint and sometimes the right, sometimes the front and sometimes the hind foot mark are measured. The techniques of measurement are not well known either.
Another counting method is photo-trapping, pioneered by Dr Ullas Karanth, one of India's leading wildlife scientists. This means literally taking photographs of tigers over a period of 45 to 60 days in a given area. The stripes on a tiger are as distinctive as the features on a human face, so photo-trapping is a means of identifying individual animals. Dr Karanth has used his method to count tigers in several National Parks, but when it was tried over an area of 80km2 in Namdapha, Arunachal Pradesh, not a single tiger was captured on film and, worse still, seven of the doctor's expensive cameras were stolen.
It appears, then, that the pug mark is still the best guide if it is used properly. Photo-trapping can be useful for carrying out a selective census of tigers in a given area, particularly where there is a good population, and the method also offers a means of cross-checking results obtained through pug marks. The real need is to improve the accuracy of the pug mark method in the first place.
WWF's Tiger Conservation Programme has now produced draft guidelines for pug mark estimates of tiger populations. Under the title of Tracking Tigers, the guidelines have been prepared by Dr L A K Singh, research officer of the Simlipal Tiger Reserve, with the cooperation of the Wildlife Institute of India. Simplified and translated into regional languages, the document could be used by trackers and field staff to obtain much more realistic census results.
Of course no counting method can be 100 per cent accurate, but what it can do is establish a clear trend among tiger populations are they going up or down? In the old days trackers and forest guards knew almost every tiger in their parks. They had a name for each animal and even knew its moods and mannerisms. They knew when the tigress was on heat, when she had a litter and sometimes even the state of the litter. Part of the aim of Tracking Tigers is to recreate elements of this vital field knowledge.
Dr Singh's guide points out that in habitats where the ground is grassy, or rocky, or composed of hard soil and it is not easy to see pug marks, artificial impression pads can be used. These could be as simple as loose soil spread over a small area on the known route of a tiger. There is also information on how to distinguish between leopard and tiger pug marks and the different marks of male and female tigers.
If the vast amount of information in Tracking Tigers can be simplified and, wherever possible reduced to graphics so that it can be used even by an illiterate tracker, there is every chance that a fairly accurate estimate of India's tiger population can be achieved and a line can be drawn under the bitter rows.
*Usha Rai works for WWF's Tiger Conservation Programme in India