Tiger populations have declined much greater than 50% over the last three generations.
Tiger populations have declined much greater than 50% over the last three generations. Comparing a breeding recent range estimate (42 “source sites” totalling 90,000 km²) to a 2006 total range estimate (1.1 million km²) suggests a range decline much greater than 50% over the last three generations (7 x 3 = 21 years). As per IUCN guidelines, generation length was calculated at seven years based on approximate age of maturity at four years, plus half the length of the reproductive lifespan of six years.
In 1998, the global Tiger population was estimated at 5,000 to 7,000 Tigers. A comparison of these population estimates of the 1990s, (many with little scientific rigour,) to similar current ones, (many of better quality,) suggests a decline of about 50%, (taking the upper bound of 7,000 as the number of mature individuals in 1993, using a precautionary approach, declining to approximately 3,500 in 2014,) but differences in methodologies and accuracy make such comparisons uncertain. This declining trend is likely to persist in the face of continuing threats such as direct poaching, prey depletion and habitat degradation which continue in all range states. Although several sites in India and Nepal have indeed reported recent recoveries, population reductions may not be reversible in other areas where Tiger habitat itself has been lost.