Counting the number of persons in a country can be done easily but counting the number of TIGERS is not an easy job. The truth is, finding out the exact number of tigers in a region is not possible. Whenever you see the number of tigers in journals and newspapers they are always accompanied by the word ESTIMATED. Yes, the numbers are estimated one's. Even estimating them is a difficult task and complex mathematical calculations are sometimes used.
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There are many methods used for counting them, the latest one being the CAMERA TRAPPING. Some of the popular methods employed are explained below.
The PUGMARK census was invented in 1966 by Indian forester SR Choudhary. In this method, during a 1-2 week period, many personnel simultaneously place the PIP's (Pug Impression pads) in Tiger tracks ( Tigers normally use human paths. Also tiger spat is located to find out the tracks). The PIP's are then collected and analysed to find the number of Tigers. The pug mark of each animal is distinct. This method gives minimum number of tigers in that region but we cant be sure that every tiger has left its mark on the pads. Experts can even tell the sex and age of the species using the pug mark.
The latest method is camera trapping where cameras are placed along the tiger paths. These cameras get triggered by the HEAT and MOTION of the animal. The pictures from all the cameras are collected and analysed to find out the number because same tiger might have been photographed more than once. An interesting fact about Tigers is that the Stripes on each tiger is distinct. This helps us pick out the
photo's of same tiger.
Both these methods leaves us with a doubt because we cant get all the tigers caught. There are other methods to estimate the number of tigers where Mathematics ( to be specific PROBABILITY AND STATISTICS) helps us.
Another fact that each Tiger has its own perimeter and they are evenly distributed in a region is used as a key. The spat (excreta) sample is collected from a particular region. The DNA analysis of this tells us the distinct number of tigers present in that area. After about a week, the same procedure is undertaken again. This time many samples which were not found in the first attempt may be found. The data's from each sampling is used to compute and finally arrive at an Estimated number.
A Tiger camera trapped is shown in this picture
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There are many methods used for counting them, the latest one being the CAMERA TRAPPING. Some of the popular methods employed are explained below.
The PUGMARK census was invented in 1966 by Indian forester SR Choudhary. In this method, during a 1-2 week period, many personnel simultaneously place the PIP's (Pug Impression pads) in Tiger tracks ( Tigers normally use human paths. Also tiger spat is located to find out the tracks). The PIP's are then collected and analysed to find the number of Tigers. The pug mark of each animal is distinct. This method gives minimum number of tigers in that region but we cant be sure that every tiger has left its mark on the pads. Experts can even tell the sex and age of the species using the pug mark.
The latest method is camera trapping where cameras are placed along the tiger paths. These cameras get triggered by the HEAT and MOTION of the animal. The pictures from all the cameras are collected and analysed to find out the number because same tiger might have been photographed more than once. An interesting fact about Tigers is that the Stripes on each tiger is distinct. This helps us pick out the
photo's of same tiger.
Both these methods leaves us with a doubt because we cant get all the tigers caught. There are other methods to estimate the number of tigers where Mathematics ( to be specific PROBABILITY AND STATISTICS) helps us.
Another fact that each Tiger has its own perimeter and they are evenly distributed in a region is used as a key. The spat (excreta) sample is collected from a particular region. The DNA analysis of this tells us the distinct number of tigers present in that area. After about a week, the same procedure is undertaken again. This time many samples which were not found in the first attempt may be found. The data's from each sampling is used to compute and finally arrive at an Estimated number.
- The estimated number is often cross checked with the PREY population in that region. Prey population plays a key role. Tiger population is proportional to the Prey population.
- The field tests are conducted in SUMMER when the availability of WATER is limited and as every animal needs water, traps placed near Waterholes will help us get a better estimation.
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