The deaths of ten tigers in the Nilgiris biosphere of Tamil Nadu between August 17 and September 19 this year caused a nation-wide outcry. Out of the ten tigers that died, six were cubs. The tigers were found in the Mudumalai Tiger Reserve (MTR) buffer zone, core zone, and Nilgiris Territorial Forest Division Area. Wildlife enthusiasts and tiger conservation experts have urged the government to take appropriate measures to conserve the tiger population in the Nilgiris biosphere.
Two cubs aged two weeks were found dead in the buffer area of MTR, while one adult tiger was found dead in the core zone of the MTR. The remaining four tiger cubs and three adult tigers were found dead in the Nilgiris Territorial Forest Division Area. Human activities are completely barred inside the core zones. The land around the core zones are called buffer zones, where limited human activities are permitted. All the zones are protected areas.
Tiger experts claimed that these deaths were not alarming but a reason to beef up vigilance outside the protected areas. Talking to TNM, Tarsh Thakaekara, a Nilgiris-based researcher-conservationist and co-founder of Shola Trust, said the tiger deaths in Nilgiris were a reason to be vigilant. "Mortality in cubs is always high in the country. The number of cubs are not monitored anywhere. Even in the recent deaths that occurred in Nilgiris, all the focus was on adults," he said, adding that the deaths of cubs came to light as the Tamil Nadu Forest Department strengthened its patrolling. "Most states never report tiger cub deaths, so it is a positive sign," Tarsh added.
The 'Patterns of mortality in free-ranging tigers' study by the Wildlife Institute of India, said that cubs’ death due to starvation and separation from mothers has been considered natural mortality. The study conducted in 2016 also revealed that a 12.5% mortality rate was recorded among tiger cubs aged less than a year. Among the cub mortality, nearly 40% had been reported during the first two months. In the study period between 2011 and 2016, only seven cases (3.5%) of cub mortality were reported. "These might be attributed to limited detection and higher chances of their carcasses being scavenged upon," the study noted. According to the NTCA report, adult females deliver 2-3 cubs (sometimes as many as 5) in one litter with 50% cub mortality, attributed to several factors, such as disease, starvation, and infanticide.
Tarsh further talked about the mother tigers that abandoned their cubs and the possibility of them poached by organised gangs. "There are many villages all along the southern edge of Mudumalai, and if they find poachers camping around, it invariably becomes common knowledge and is reported to the Forest Department and police," he noted.
While talking about the deaths of four adult tigers, he highlighted that two tigers were old and died during infighting. "The remaining two died due to poisoning by humans. To prevent such things in the future, the government should give monetary compensation to those who lost their cattle, which should be done fast and in line with the market prices of the cattle. In carnivore-human co-occurrence zones, the government should also proactively give subsidies for other livelihoods that don't involve livestock, rather than only reactively give compensation after kills happen," Tarsh suggested.
Read: Ten tiger deaths in 34 days in Nilgiris: Starvation, poisoning suspected
He pointed out how the lack of prey availability inside the forest pushes the carnivores to roam outside the protected areas. According to him, over the last 15 years, nearly 40 tigers have established their ranges outside of protected areas. "While forests have been diverted in many parts of India, in the Nilgiris forest boundaries have been more or less stable since 1900, with only minimal encroachment. But importantly, the forest quality has reduced considerably with about 40% of the region lost to toxic invasive species of plants like Lantana camara and Senna spectabilis, making it uninhabitable for most animals, pushing them out of forests," he added. The government has recently started trying to manage this more proactively but it would take a very long time to clear invasive plants from significant areas of forests and improve the quality of habitats, he noted further.
Jeswin Kingsly, a senior naturalist at Tadoba Tiger Reserve, seconded Tarsh's thoughts and said the tiger population was concentrated in more areas than the habitats that support it. Jeswin, a native of Nilgiris and who worked in Project Tiger - Nilgiri Landscape as a field assistant in 2016, said "The number is not as alarming as the media portrays," he said, adding that the increased tiger population could be one of the reasons for the deaths of four adults. "The tiger population in Nilgiris is increasing where tigers were sighted out of protected areas and very close to human habitations," he noted.
Talking about the mothers of the cubs who died in Nilgiris, he said that finding the reason behind the vanished mothers would give more clarity about the scenario. "If it is poaching, then I would not be surprised because I saw five tigers, a mother, and her four cubs, in very vulnerable locations in September out of protected areas. Tiger presences in tea and coffee plantations – far away from protected areas and forests – were reported frequently," he added and urged the Forest Department to bolster the vigilance outside the protected forests.
The Nilgiri cluster in the Western Ghats has one of the highest densities of tigers in the state. According to the Status of Tigers, Co-predators and Prey in India, 2022 report, the total estimation of tigers in the Western Ghats landscape in Tamil Nadu is 306. In MTR, which is contiguous with Bandipur of Karnataka, Wayanad of Kerala, and Sathyamangalam Tiger Reserve of Tamil Nadu, 114 tiger individuals were identified. The tiger density was 7.73 tiger per 100 sq km. The sex ratio was 1 male per 1.5 females.
"We need to look beyond the deaths. The pattern, strategy, numbers, the territorial range, contiguous forest availability of the free-range wild tigers" said Pravin Shanmuganandam, founder of Pollachi Papyrus, an online portal that documents the bio-cultural diversity of the Western Ghat region in Tamil Nadu. "The Nilgiris biosphere – which includes Wayanad of Kerala, Bandipur of Karnataka, and Sathyamangalam – has nearly 400 tigers. But if we are looking at the habitat, the place simply cannot hold that population of the tigers," Pravin added.
Tigers roam across large areas called home ranges. The home ranges are usually determined by the availability of the food. "It is usually 60 to 150 sq km for male tigers, female tigers use 20 to 60 sq km. If we consider this, the Nilgiris biosphere could not hold the total population of the tigers in the area," Pravin detailed, adding that lack of forest cover should be considered when it comes to tiger deaths.
Tigers are solitary animals and do not share space with siblings or offspring. So, once the cubs hit a subadult state (1 to 3 years old), tigers move to find their territories. If the protected area already houses more tigers, then push-pull action would take place where younger tigers chase weaker and older tigers out of the territory to occupy the place or keep moving outside the protected area to have unoccupied territory. It is the case of two other tiger deaths that occurred in Nilgiris during the said period.
The National Tiger Conservation Authority (NTCA) report on October 6, said the deaths were not alarming in the context of current population size growth, dispersal dynamics, and behaviour patterns of the mother tigers in the landscape. NTCA urged the tiger management to bolster the prevention measures.
Read: Tiger deaths in Nilgiris due to natural causes, says NTCA report