Context: Recent data from an unreleased elephant census, which incorporated new counting techniques, has revealed a decline in elephant populations across several regions of India, particularly in southern West Bengal, Jharkhand, Odisha, and Kerala.
Previous Counting Methods
Total Direct Count
- Up until 2002, India used the “total direct count” method, which involved a simple headcount of the elephants spotted.
- This method, however, had limited scientific validity, especially when applied to large landscapes.
Sample Block Counts
- Later, the method evolved into “sample block counts,” where smaller areas of around 5 square kilometers were surveyed, aiming to improve the accuracy of elephant detection and enumeration within those blocks.
Indirect Dung Count Method
- Introduced in 2002 in the southern states, the “indirect dung count method” estimated elephant density based on the “defecation rate” of the species, using dung as a proxy to determine population numbers.
New Approach
Harmonising Population Estimation Methods
- On World Elephant Day (August 12) in 2021, the Environment Minister announced a move to “harmonise population estimation methods” by integrating elephant and tiger population surveys for the first time.
- The new method divides the forest into cells or blocks (e.g., A, B, C, D), where ground surveys are conducted, not only for tiger signs like pugmarks or droppings but also to assess factors such as vegetation quality, prey availability, proximity to water, human disturbance, etc.
- Unlike tigers, elephants lack distinctive markings. Thus, dung samples collected during these surveys are analyzed in laboratories, using genetic markers (specifically eleven microsatellite loci) to differentiate and identify individual elephants.