No glitches in tiger estimation numbers, claims WII

Dehradun: Scientists of the Wildlife Institute of India (WII) as well as officials of Corbett Tiger Reserve (CTR) on Friday reacted to a media report which alleged that there were glitches in the tiger estimation exercise of 2015 conducted by WII and National Tiger Conservation Authority. The exercise had counted 2,226 tigers and photographed 1,635 but it was alleged that 221 of these “tiger photos” — or around 16% of the numbers — should not have been counted as it was found “after an analysis of the pictures that one of seven could be a paper tiger photographed twice; in some cases even thrice; photos repeated, and photos repeated but shown as that of different tigers in the data set.”
YV Jhala, senior scientist of WII and principal investigator of the tiger estimation report said that “there is no question of duplicating or inflating the numbers as we still have the data and albums very much saved with us.” Providing a detailed response on how the numbers were arrived at, Jhala said, “ For population estimation, tigers above the mid-shoulder height of mothers were included in the analysis, while photographs of all tigers are included in the photo album which is being cited to infer that numbers were inflated by 16%.” He added that “for population estimation of a site, we use either the left or right flank photos of tigers with single captures, depending on which flank has larger number of individual tigers for that site.” “The photo album has photos of all single flank tigers (both right and left) since this information is useful for solving poaching cases as well since at a later date, when the same tiger is again photo-captured by both flanks, its ID can be updated in the database.Though young tiger photos (cubs, juveniles etc) are shown in the photo album, these are not used for population estimation. The purpose of putting these photos in the album is related to their use for solving tiger crime and for understanding tiger demography (dispersal, survival, etc.).”
He added that the numbers have in fact been under- reported. “With the amount of conservation work that we have carried out in the past few years, I can say that the tiger count in the country would in all likelihood be much more than the numbers we could capture.”
In a similar vein, director of CTR, Rahul (who uses only his first name), said, “Wildlife estimation is a very dynamic thing as it is impossible to count all the animals in a jungle. In Corbett Tiger Reserve for instance, we have hilly areas where camera traps are impossible to put. Similarly, in the Kalagarh reserve area, it is difficult to put double cameras in the 2 sqkm grid since the area is filled with several water-bodies making the task of installation impossible.” He added that “even if one assumes that there is a 16% extrapolation as is being alleged, that is hardly a significant number given the vastness of the data that is being surveyed.”