Tiger

The tiger, Panthera tigris, is a species of Felidae in the taxonomic genus Panthera. A striped individual encountered in the field is both a member of that species and a particular animal with its own movement and detection history.^[ref]

This distinction made a useful measurement technique possible. A 1995 study in Nagarahole used camera traps along travel routes and identified individual tigers from photographs. Thirty-one photographic captures across nine sampling occasions represented ten different animals, not 31 animals. Their capture histories were then analyzed using mark and recapture methods that allowed different individuals to have different detection probabilities.^[ref]

For an original toy capture history, write 101 for an animal photographed on the first and third occasions, and 010 for another photographed only on the second. These are three detections but only two known individuals. Animals never photographed leave no such history, which is why an abundance estimate needs a detection model in addition to a tally.

The method connects a natural visible marking with statistical identification. It also exposes a limitation: placing cameras on travel routes samples encounters with those cameras, rather than guaranteeing that every tiger in the study region has been seen.