< Previous | Contents | Next >
♤ The process of estimating the number of tigers in a given area is called ‘Tiger census.’
♤ This exercise provides us with an estimate of tiger number, density and change in tiger indices - a measure of tiger occupancy in a given area.
♤ It is conducted at regular intervals to know the current tiger populations and population trends.
♤ Besides estimating the number of tigers the method also helps to gather information on the density of the tiger populations and associated prey.
♤ The most commonly used technique in the past was ‘Pugmark Census Technique’. In this method the imprints of the pugmark of the tiger were recorded and used as a basis for identification of individuals. Now it is largely used as one of the indices of tiger occurrence and relative abundance.
♤ Recent methods used to estimate the numbers of tigers are camera trapping and DNA finger-printing.
♤ In camera trapping, the photograph of the tiger is taken and individuals are differentiated on the basis of the stripes on the body.
♤ In the latest technique of DNA fingerprinting, tigers can be identified from their scats.
2010 Assessment Methodology
♤ The All India Tiger Estimation exercise is one of the most crucial components of our national tiger conservation efforts.
♤ Since 2006, this monitoring exercise is being undertaken every four years.
♤ This report presents the results of the 2010 National Tiger Assessment, undertaken through a best-in-class scientific process.
♤ This presents an estimate of India’s current tiger population and a broader assessment of our tiger landscapes.
♤ The three phases of the tiger estimation procedure are as follows:
♤ Phase 1: Field data collected at the beat-level (i.e. the primary patrolling unit) by trained personnel using a standardised protocol.
♤ Phase 2: Analysis of habitat status of tiger forests using satellite data.
♤ Phase 3: Camera trapping was the primary method used where individual tigers were identified from photographs based on their unique stripe patterns. This information was analysed using a well established scientific framework. Camera trapping was carried out by teams of wildlife biologists and local forest personnel.
Based on the tiger numbers recorded in sampled sites, an estimate for other contiguous tiger-occupied landscapes, was made. For this, additional information such as tiger signs, prey availability, habitat conditions and human disturbance was used. Thus, the final estimates provide a comprehensive and statistically robust result for the whole country