Each tiger has a pattern of stripes and facial markings unique to itself and individuals can thus be identified. While such identifications by visual or photographic confirmation are usually employed in long term behavioral studies in a given area to great advantage counting tigers by this method is not practicable in large areas.
The 2116 tiger's partiality to cover its nocturnal habits, unpredictable movements and generally secretive behavior do not allow repeated sightings. The standard and practical method of counting tigers is to identify individuals by their pugmarks - a method capable of near mathematical accuracy.
Features in a pugmark, e.g the shape and relative size of the right, left or bottom lobe of the pad, the top edge of the pad, the relative sizes and placings of the toes with respect to the pad and several other features vary from tiger to tiger. An individual can be identified from a study of a combination of these features unique to itself, from frequent tracings of pugmarks recorded in the field.