THE TIGER CHANGING ITS STRIPES?

It's seen such an unalterable fact of nature that it has yielded a proverb: a tiger cannot change its stripes. But that’s exactly what India’s iconic national animal is doing.

- Rohit Parihar

Something curious is afoot in the slender pool of tigers left in our pockets of wilderness—and it’s hap­pening precisely because the pool is so slender. Inbreeding is inevitable, and its consequences are showing up in a startling visual metaphor. Gene mutations have led to tigers being born with wider black stripes in Odisha’s Simlipal Reserve. These apparent freaks of nature—being called “black tigers”—have a precursor. White tigers, a dismal product of inbreeding, have been known in American zoos since the 1950s. Animal geneticists are worried. Such tigers typically have severe defor­mities such as cross-eyes and cleft lips, besides high mortality rates. In Sariska, Rajasthan, a blind cub born two years ago—and dead within months—was ascribed to the genetic curse. The spectre of decay in isolated tiger popula­tions due to mating between closely related individuals—called ‘inbreeding depression’—is now driving what could be India’s first attempt to intervene in the genetic diversity of the big cat.