Why are tigers losing their stripes in India?

Find out why nature restoration threatens to turn this jungle icon black.

The Similipal Tiger Reserve in eastern India is home to tigers with a unique coat: their orange fur is largely dominated by broad black stripes. This rare genetic mutation, known as pseudomelanism, affects about half of the reserve’s roughly 30 tigers. This dark coat is harmless in itself, but it’s a sign of a more serious problem: inbreeding caused by isolation.

Several decades ago, India’s tigers were on the brink of extinction. Thanks to enhanced protection, particularly through the National Tiger Conservation Authority, their numbers have risen from about 1,400 in 2006 to more than 3,100 in 2022. Similipal, one of the largest reserves, has seen its population grow from just four tigers in 2014 to a more stable number. But this reserve is a veritable “tiger island.” It is surrounded by towns, villages, and farmland, with no functional corridors to neighboring reserves such as Satkosia (where there are no longer any tigers) and the Sundarbans.

Since tigers can hardly enter or leave Similipal, the gene pool there is limited. The rapid spread of pseudo-melanism, caused by a natural DNA mutation, demonstrates how quickly traits can spread in the event of inbreeding. Experts warn that harmful mutations can also arise in this way, threatening the species’ long-term survival. The goal is no longer simply to count tigers, but to restore genetic diversity.

Creating genetic diversity

That is why park rangers, conservationists, and geneticists are collaborating on a targeted breeding program. Uma Ramakrishnan, a molecular ecologist at the National Center for Biological Sciences, is studying the DNA of both living and historical tigers. He is even examining stuffed specimens from old hunting collections to find the best genetic matches. Meanwhile, field teams are searching for males like T12, an elderly, mostly black tiger who plays a central role in plans to establish new, healthy bloodlines.

Without intervention, the Similipal tiger population risks genetic collapse. Today, conservation requires much more than simply protecting habitat. It requires breaking down isolation and ensuring a resilient future for this unique part of India’s natural world.