India, July 29 -- This is the fourth of a 4-part series. Read the first, second and third parts.

K Ullas Karanth, a Bengaluru-based wildlife biologist, says the first step could be to reduce prey densities to natural levels by stopping manipulations and restoring habitats to natural conditions. "You cannot pack territorial big cats at ever-increasing densities. Relocating tigers is not a solution. For every success claimed there have been a dozen failures, with tragic consequences which are forgotten and buried," he says.

Karanth adds that only at sites where habitat and natural prey have been recovered through protection, and where there is no option for natural dispersal of tigers from higher density areas, should artificial relocatio...