The population of tigers in India is declining due to habitat loss, prey depletion, poor genetic diversity, habitat degradation, the illegal wildlife trade, man/animal conflict, tourism, and lack of a wildlife management and protection infrastructure.
Since the early 1900s when their population was numbered in the tens of thousands, poaching and habitat destruction have devastated India's tigers. An adult tiger requires 6,600 pounds of living prey, or about 50 deer-size animals, every year. The quantity of prey available depends on the habitat, and environmental encroachment by humans reduces tiger food sources. The main cause of population decline is starvation and habitat loss, followed by poaching for luxury trade. In 2011, Interpol estimated the value of the illegal wildlife trade in the world to be at $32 billion. Tigers in areas around parks are easy targets for poachers. For long-term protection of tigers, these areas need to be secured, but forest and wildlife preservation are not high on government priority lists. As a result, little money is dedicated to habitat preservation, and the penalties and conviction rates for poaching are low. Urbanization and fragmentation in tiger corridors also limit genetic exchange between tiger populations. Isolated populations with lower genetic diversity provide another threat to survival.