Prakash Chand Gogineni, Field Director of the Similipal Tiger Reserve in Odisha, is still coming to terms with the thrill of a moment he witnessed on May 28. A camera trap had captured a rare sight of a tigress named Zeenat, gently carrying her four cubs one by one in her mouth. Gogineni saw the images in his modest office in Baripada, the district headquarters of Mayurbhanj, where Similipal is located. He knew immediately that he was experiencing a key moment in India’s wildlife history.

Zeenat is one of the two tigers introduced into Similipal from Maharashtra’s Tadoba-Andhari Tiger Reserve through translocation in 2024. “Similipal was heading towards a genetic collapse, largely due to inbreeding among big cats. While the tiger population was stagnating, the rising number of pseudo-melanistic tigers in the reserve had become a matter of concern,” recalls Odisha’s former Principal Chief Conservator of Forests (Wildlife) Susanta Nanda.

Pseudo-melanistic tigers (often called black tigers) are a rare variant of the Bengal tiger, distinguished by a genetic mutation that causes their black stripes to widen and merge, giving them a dramatically dark coat where slivers of golden yellow barely peek through.

It was during Nanda’s tenure that the two tigresses were introduced to Similipal. He says Zeenat’s translocation to Similipal was a necessity, not an experiment. “Maharashtra agreed to part with nine tigers (seven females and two males) in three phases over five years,” he says.

Similipal, which derives its name from simul or the silk cotton tree, is a 2,750-square-kilometre UNESCO Biosphere Reserve. In 1973, the Indian government declared it a tiger reserve.

Currently, Gogineni says his priority is the safety of the tigress and her cubs. “This can be seen as India’s first successful inter-State tiger translocation from a reserve with a surplus population to one with low density,” says the 48-year-old Indian Forest Service (IFS) officer, who has been tracking Zeenat for 20 months.

“The tigers were brought to Similipal, where breeding females already existed, a scenario that had not occurred earlier,” Gogineni points out. He believes the development could serve as a compelling case study for future efforts to revive tiger population.

Genetic decoding

This is Odisha’s second attempt at translocation — a process of bringing tigers into a new habitat. In 2018, the State brought in two tigers from Madhya Pradesh’s Kanha Tiger Reserve and Bandhavgarh Tiger Reserve to its Satkosia Tiger Reserve. Central India tigers were believed to adapt to the terrain and ecosystem of Odisha faster than those of States further away. The operation went haywire. One of the tigers was poached; the second was returned to its home State due to resistance by locals.

Earlier, translocations in India were aimed at reviving tiger population within States. Spearheaded by the National Tiger Conservation Authority (NTCA), Sariska Tiger Reserve in Rajasthan saw India’s first successful tiger reintroduction in 2008. In Madhya Pradesh’s Panna Tiger Reserve, NTCA and the Wildlife Institute of India (WII) conducted a similar programme in 2009. In both cases, the tigers came from within the States.

In 2021, molecular ecologist Uma Ramakrishnan, who is also a professor at the National Centre for Biological Sciences, Bengaluru, and her co-researchers found that Similipal’s tiger population remained small and isolated with minimal genetic exchange with other landscapes.

In her tiger population genetic analysis, presented in PNAS, a multidisciplinary scientific journal established in 1914, she and her team found that “Similipal has a small and isolated population.” In the paper ‘high frequency of an otherwise rare phenotype in a small and isolated tiger population,’ the team found that approximately 37% of Similipal’s tigers were pseudo-melanistic. “Small and isolated populations have low genetic variation...making them prone to extinction,” the paper said. It also makes the population more vulnerable to diseases.

“These factors might also lead to greater genetic load (harmful genes) in the population. The translocation aimed to reverse all of these. For the long-term survival of a species such as the tiger, genetic diversity becomes the bedrock,” Gogineni emphasises.

The 2014 All India Tiger Estimation (AITE), a four-yearly survey led by NTCA and WII, recorded a drastic decline in the tiger population in Similipal to just five individuals (one male and four females). Only one of them exhibited the pseudo-melanistic coat pattern, placing its prevalence at 20%. Subsequent AITEs in 2018 and 2022 indicated a recovery in numbers from five to eight and then 16 tigers. However, the rise was accompanied by the worrying genetic drift: pseudo-melanistic tigers increased to 37.5% in 2018 and 43.75% in 2022. The 2023 All Odisha Tiger Estimation, a State-level survey and census conducted by the Odisha Forest Department, found that nearly half of Similipal’s tiger population displayed pseudo-melanism. The 2024 AITE further raised concern putting the figure at 59.37%.

Nanda says it was not easy to get tigers from other States. “With a comprehensive report detailing pseudo-melanism in tigers, a strong prey base, and an increased patrolling system in Similipal, we approached the Ministry of Environment, Forest and Climate Change. After much persuasion, the Ministry agreed and the approval of the NTCA followed in May 2024,” he recalls.

From Maharashtra to Odisha

The approval paved the way for the translocation. Jamuna, 2.5 years, was released in October 2024 into a specially designed soft enclosure at a meadow in southern Similipal’s Jenabil.

Two weeks later, on November 15, Zeenat, the second tigress from Tadoba-Andhari, then three years old, was released in the early hours into an enclosure at Tiger meadow in Chahala, in northern Similipal.

Learning from the setbacks in Satkosia, the Similipal authorities made extensive preparations. A team comprising two Deputy Directors (IFS officers), 15 tracking personnel, along with a veterinarian and a biologist, led by Gogineni was sent to Tadoba for specialised training. The tracking teams were trained in very high frequency (VHF) telemetry and other monitoring systems.

Jamuna made her way to the Kuldiha forest, which lies outside Similipal’s core area. She has since remained there. Zeenat, however, traversed three States: Odisha, Jharkhand and West Bengal. This is now regarded as one of India’s most intense pursuits of a single tiger, says Nanda.

Zeenat was kept in the soft enclosure for 10 days. Just three days after she was released into the wild, she began moving in the north-west direction. Ten days later, she was sighted in the Musabani range near Jamshedpur in Jharkhand. By then, Odisha had already deployed a special team to tranquilise her and bring her back to Similipal.

The operation to track and recapture Zeenat lasted over a month and involved nearly 200 personnel, including senior IFS officers, biologists, veterinarians, and tracking teams. The teams pursued Zeenat over nearly 300 kilometres.

“From day one we sensed that Zeenat was both headstrong and intelligent. She would do exactly what she chose to. We simply couldn’t force a response from her,” says Swarup Fullonton, a wildlife biologist with the Similipal Tiger Reserve and a key member of the tracking team.

“We had never experienced such a chase in our lives,” Fullonton recalls.

“On a couple of occasions Zeenat was right behind us. The tracking antenna showed zero gain, meaning there was virtually no distance between her and us. At times, it registered three to six gains, indicating she was within 12 feet,” he describes.

As Zeenat moved across States, the operation demanded close inter-State coordination. Biologists and veterinarians from3 all three States endured long hours inside camouflaged vehicles, often in sub-zero night temperatures. At times, they climbed onto elephants or were hoisted by earthmoving machines to gain a clear line of sight.

Finally on December 29, the tigress was tranquilised near a dam area in the Ranibandh Range of West Bengal’s Bankura district. Gogineni says the West Bengal government was reluctant to hand Zeenat over to Odisha, but he and the NTCA teams persuaded the authorities and the tigress was brought to Similipal through a green corridor, with wildlife veterinarians and biologists keeping a close watch on her health while administering the sedative.

Once Zeenat reached Similipal, authorities placed her inside a soft enclosure spread over 7 hectares under 24-hour surveillance. Gogineni says, “As the days passed, the local resident male T12 visited the enclosure and we could record their interactions through a bispectral thermal camera (capturing both images and heat).”

In April 2025, Zeenat was released into the wild. “Zeenat’s mating with T12 did not result in any cubs. The tigress subsequently changed her territory twice and finally mated with T45 in January this year and delivered four cubs in May,” says Gogineni.

Fantastic four!

Nanda says India’s tiger conservation programme is facing the challenge of habitat connectivity. “In that context, Zeenat broke the barrier of discontinuity in the habitat.” Now 25% of cubs in Similipal have a diverse gene pool and it will grow stronger in three-four years if Zeenat’s cubs survive, he adds.

Gogineni is optimistic too. “Currently, there are 32 tigers in Similipal. As the tiger population in Similipal reaches its carrying capacity of 75, tigers from the reserve will move towards the forests in Keonjhar, Dhenkanal, Deogarh, and further to south into Angul districts and maybe to Satkosia Tiger Reserve,” he says.

Towards the north, tigers will be dispersed in all the forests of the Chota Nagpur Plateau. “This can potentially repopulate tigers in Saranda forests, Palamu Tiger Reserve, Jhargram forests and beyond into Mayurjharna Elephant Reserve. The movement of males will be quick, but females might take longer,” adds Gogineni.

This inter-State tiger translocation programme has achieved its medium-term objective. Now, Odisha awaits the decision of a high-level committee on the translocation of the remaining seven of the nine tigers from Maharashtra. Of these, six (five females, one male) were to be translocated to Similipal, while the other three (two males and one female) to Debrigarh Wildlife Sanctuary.

If Jamuna comes into estrus (in heat) and Zeenat is ready to mate over the next 18 months, the tiger population could grow naturally. In that case, the proposed translocation of seven more tigers from Tadoba may be reconsidered.

satyasundar.b@thehindu.co.in

Edited by Sunalini Mathew and Amarjot Kaur