th rates , suggesting that hunted individuals far exceeded 57,000 (98% of the ancestral effective size), even in peninsular India. Accounting for population growth rates suggests that our genetic results might be in concordance with historical hunting records. Our estimates of the decline are linked to the assumed Ne/N ratio of 0.4 . Empirical estimates for mammals suggest a median Ne/N of 0.6  while theoretical estimates suggest Ne/N of 0.5 . These estimates would reduce the decline to 97.4% and 97.8% respectively. Alternatively, Ne/N values lower than 0.4 would accentuate the decline scenario we propose.
It is known that in the last ∼600 years, two major historical events  affected tiger populations across the Indian subcontinent: the intrusion and political control of India by Mughal' warriors who were known for their advanced hunting technologies, and subsequently, the establishment of the British Empire, which promoted widespread use of fire-arms, modern technologies and encouraged mass hunting of tigers for bounty and sport. Our results estimate the median timing of decline to 200 years ago, overlapping with the extensive bounty killings, which started around 130 years ago under colonial rule . Historical records indicate that tigers were systematically hunted from Mughal times (around 500 years ago, ) and the subsequent colonial rule additionally encouraged bounty-hunting (initially in eastern India) from about 1777 (231 years ago) . It is possible that tiger population declines started during the Mughal empire and accelerating over the last 150 years during colonial rule. The analytical approaches we use in this paper explore relatively simple scenarios of decline. However, additional historical genetic data from trophy or bounty hunted tiger skins might allow investigate as to whether rates of decline in tiger populations have increased relatively recently. Finally, our estimates of the timing of decline are based on an assumed 5-year generation time for tigers . A higher generation time (say 6 years) would result in a younger estimated timing of decline, while a lower generation time would result in an older estimated timing of decline.
The differences between the observed patterns of population differentiation between mitochondrial and nuclear markers could be because of the lower effective size for mitochondrial DNA , or due to interactions between mode of inheritance and sex-biased dispersal. Female tigers have smaller home ranges than males, with daughters inheriting the home range of their mothers . This would result in strong population subdivision for maternally inherited mitochondrial DNA. On the other hand, biparentally inherited nuclear (microsatellite) data are consistent with expectations for a large carnivore species that exhibits long-range dispersal movements . Discordant patterns for population differentiation between mitochondrial and nuclear DNA are common for mammals with female philopatry and male-biased dispersal . It is interesting that population subdivision between Southern and Central India is not significant for both mitochondrial and nuclear DNA, suggesting dispersal through a wide range of habitat types as well as relatively recent fragmentation of the formerly contiguous tiger habitats in peninsular India.
Implications for conservation
Our results are important for global tiger conservation because they suggest that Indian tiger populations are critical for species recovery. However, because tiger habitats in India are often small, disjunct and fragmented, conservation options are limited. Ecological studies ,, have identified a few protected landscapes in India with high tiger densities and potential connectivity. Conservation efforts must prioritize these tiger populations in larger landscapes like the Western Ghats, Central India and the alluvial flood plains in the Himalayan foot hills that support high potential tiger densities, and relatively larger populations.
Genetic diversity retains the history of a species ,, and is vital for survival and future adaptation to changes . A