The problem with a perfect fence
Kanha Tiger Reserve has been protected since 1955. Pench since 1977. For decades, both reserves ran camera-trap surveys, anti-poaching patrols, and strict buffer-zone rules. Tiger numbers inside each park held steady, then grew modestly. But the populations were not truly recovering, they were holding. A 2013 study published in PLOS ONE by researchers including those from the Wildlife Institute of India found that isolated tiger populations in fragmented habitats showed measurably lower genetic diversity than populations connected by functional corridors. The fence that kept poachers out also kept tigers in.
