Here is the eighth part of an article published by Shri Vinod Rishi in The Indian Forester. Vol.136:10. Wild Life Special. Shri
Vinod Rishi is IFS – retd. and a Former Additional Director General of Forests (Wildlife), Govt. of India;
(Continued from last month)
(4) Evaluation of the Conclusion
Derived in the Review
The bench-mark for the evaluation of census data was defective, the experiment fell short of simulating either of the two field methodologies and the inherent flaws in the design and conducting of the experiment insulated it from the field methodologies. With
sample survey, the only interpretations one can arrive at are:
1) That it is difficult to count tigers from only one parameter – pugmarks from two soil substrates provided in the experiment; and
2) That the shortfall in the skills exhibited by participant in a single trial cannot be treated as the defect in the methodologies.
(B.II). Pugmarks are a reliable tiger monitoring index – can be used in estimation of tiger populations and research – Other Views:
a. In the follow-up of his Critical Review of Field Censuses in 1987, the investigator re-iterated that the pugmarks are not unique to individual tigers; they cannot be used for census, but can be used for estimates;
census is subjective and number game; the census method is not validated quantitatively on wild tigers; and the field method is vulnerable to extraneous factors
I. Research on the specific points mentioned above was conducted by the scientists of the Wildlife Institute of India. The findings conclusively disproved all these contentions in 2005 (Sharma et al, 2001, 2005).
II. The study established that the pugmarks are unique to individual tigers; pugmarks can be used for population estimation of tigers; 63% of the Indian experts were 100% accurate in identifying tigers from their pugmarks;
pugmarks census technique had 100% classification accuracy in DFA & Logistic Regression models using only two variables -
Length & Width of pugmarks; and that the use of protocols can help in avoiding influence of extraneous factors (Sharma et al, 2001, 2005).
b. Based on a long-term monitoring work in Chitwan Park in Nepal since 1980, using radio-telemetry in a 100 sq km high density tiger occupancy area, Charles McDougal, a Smithsonian Research Associate, made the observation
that it was possible to distinguish the tracks of an adult male tiger from those of an adult female, and that it is possible to differentiate between adults of the same sex from their pugmarks, especially if the animal’s
feet have been injured, leaving particular patterns of the toes in relation to each other and to the pad
(McDougal et al, 1999).
c. A tiger pugmark-identity correlation field test was carried out by the scientists of the
Smithsonian Tiger Conservation Project in Chitwan tiger habitat in Nepal. It involved identification of tigers from their tracks and verifying their identity from photographs of tigers. The team established the validity of pugmark identification in 1996, and
extensively used data from tracks in their research work for over 15 years. They were confident that In
the future tiger researchers will be able to collect even greater amounts of auto-correlated data in a repeatable fashion using GPS collars, and believed that this approach will allow researchers to combine information from tracks, radio locations and GPS to
limitations of each type of data (Smith et al, 1999).
d. If pugmarks could not identify individual tigers and leopards, how is it that Jim Corbett
did not overkill tigers and leopards in his pursuit of man-eaters, at a time when for every tiger and leopard in India today there were many times more in his times to choose from?