Research overview: prey depletion and the empty forest syndrome for tigers

An overview of how the loss of large ungulate prey to human hunting hollows out tiger habitat even where forest cover remains, producing empty forests that cannot support tigers. Because tigers require abundant large prey, overhunting of sambar, deer, wild pig and gaur is a primary, often underestimated driver of tiger decline across Southeast Asia, frequently preceding the loss of the cats themselves. This survey synthesizes evidence linking prey biomass to tiger density, the snare-hunting crisis depleting prey, and why protecting forest without protecting prey fails. It connects to prey-based conservation theory and to the broader defaunation literature. The topic reframes tiger conservation around restoring and defending the prey base, identifying prey depletion as a key, addressable threat.