Why does the filming of a rare 'golden' tiger in India worry conservationists?

CNN
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When tour guide and wildlife photographer Gaurav Ramnarayanan set out on safari on the evening of January 24, 2024, he wasn't looking for tigers.

The 25-year-old was leading a private tour of UNESCO World Heritage Site Kaziranga National Park, A 430 square kilometers A wildlife sanctuary in the northeastern Indian state of Assam. Although it is home to the largest population of tigers in the region, sightings are rare and the park is famous for its other wildlife, including the largest population of one-horned rhinos in the world. favorable A type of colorful bird.

This is what Ramnarayanan and his guests were looking for that night. While sitting in their safari jeep in the late afternoon, the group suddenly heard the alarm call of a deer – the sound an animal makes when it sees A predator, says Ramnarayanan. He started driving, turning a corner before stopping the car in its tracks: about 700 meters away, there was a tiger on the road.

“At first when I saw him, he looked white and did not look like a normal (Bengali) person.” says Ramnarayanan, who has been guiding wildlife tours and photographing big cats since 2016, when he founded his travel company The Wildside. “I've seen enough tigers to know at first glance that this one was no ordinary one.”

His suspicions were proven correct when he looked at the predator through the camera lens: the big cat, with its strawberry-blonde stripes, was without a doubt a rare “golden” tiger.

“The leopard decided to come towards us, not with the intention of attacking or any intention to harm us, but just to cross its path and move forward to mark its territory,” says Ramnarayanan. He was able to capture amazing shots of the tiger as it walked along the road, 100 meters away from the jeep.

Ramnarayanan posted a photo online, and netizens were quick to express their admiration for the stunning photo and the unusual coloring of the tiger.

But golden tigers — also known as golden tabby tigers or strawberry tigers — are not a subspecies: they are the result of a genetic mutation that changes the color of their fur.

Despite her beauty, her existence has a dark side.

Golden tigers, like white and snow-white tigers, are the result of a recessive trait that manifests as a mutation in color-producing genes, says Uma Ramakrishnan, a professor of ecology at India's National Center for Biological Sciences.

She likens the mutation to “spelling mistakes in DNA” that lead to different color combinations. In white tigers, the mutation prevents color, while in golden tigers, a mutation in the so-called “broadband” gene prolongs the production of pheomelanin, a reddish-yellow pigment, during hair growth. Snow-white tigers inherit both recessive traits, giving them a white coat with barely visible blonde streaks, giving them the nickname “unstriped tiger.”

And in the wild less than One in 10,000 Tiger cubs are born with white fur, and golden fur is much rarer.

That's why conservationists worry that the emergence of these tigers may be a symptom of inbreeding in isolated tiger populations.

It's more common to see these unusual fur patterns in captive groups of tigers, which are often related to each other, Ramakrishnan says. Historically, tigers were white Selectively bred These genes, often with their offspring – which is why, while there are currently no known white tigers in the wild (the last ones are said to have been… Was spotted and shot in the 1950s), it's over 200 In captivity around the world.

While irregular fur coloration is not known to have adverse health effects, Endogamy “It can cause physical ailments including a flat face or crossed eyes, as well as other genetic mutations that can weaken a tiger's defense against disease,” Ramakrishnan says.

there Estimated at 30 Golden tigers are in captivity around the world, according to some sources, and Kaziranga National Park claims to have them fourthe only one known in the wild.

Given the exceptional rarity of this trait, “the only way it would emerge,” Ramakrishnan says, is through inbreeding or Genetic deviationany It is when rare genes become more common by chance, something that is still being studied.

Golden tigers have been spotted in Kaziranga since 2014, and Ramnarayanan is not the only one to have captured them on camera: in 2020, a Mumbai-based photographer Mayrich Hendry He shared pictures from his safari in Kaziranga online, which also created a stir online.

Although it's a unique selling point for visitors, the park isn't celebrating: in a statement posted on the park's website X account (formerly Twitter) in 2020“Recessive genes arise due to inbreeding among a fragmented population,” said Rabindra Sharma, research officer at Kaziranga.

around 70% of Assam's 190 tigers They live in Kaziranga, but rapid development in the area means that wildlife is losing their historical migration routes between habitats. a Study 2020 Increasing fragmentation and loss of forest corridors around the park have been documented. If Kaziranga's tigers become more isolated, issues such as inbreeding will threaten the population, he said Sharma in his post on X.