Eravikulam National Park Holds 841 of the 2,668 Nilgiri Tahr Counted in April 2025, the Largest Contiguous Population of a Mountain Animal Found Only in the Western Ghats

Eravikulam National Park above Munnar in Kerala holds an estimated 841 Nilgiri tahr, the largest contiguous population of a mountain animal found nowhere else but the Western Ghats. The figure comes from a synchronised survey that the Kerala and Tamil Nadu forest departments ran from 24 to 27 April 2025. It counted 2,668 tahr in the wild, 1,365 in Kerala and 1,303 in Tamil Nadu, according to the Kerala Forest Department’s report of August 2025.

The Nilgiri tahr (Nilgiritragus hylocrius) is one of three tahr species in the world, alongside the Himalayan and Arabian tahr, and the only one restricted to the Indian subcontinent, the report says. It lives on grassy slopes next to cliffs. The report’s age classes describe an adult female as more than 70 cm at the shoulder and an old male, called a saddleback, as about 110 cm with a pale patch across the back. IUCN lists it as Endangered, and it is protected under Schedule I of the Wildlife (Protection) Act, 1972.

How four mornings on foot produced the number

Each survey block was walked over four consecutive days, with field work starting between 6:30 and 7 am, the Kerala report says. Each team had a forest official, a local field watcher and a volunteer, and they logged each herd’s direction, the time and the GPS position so that one herd was not counted twice. Counters sorted the animals into five age and sex classes, from newborns about 45 cm tall to saddlebacks.

Inside Eravikulam the department used the bounded count method. It takes the counts from the four days, each of which misses some animals, and builds an estimate from the largest and second-largest. The result was 841, with a 95 percent confidence interval of 828 to 880. Perumalmala (154), Naykkolli A (144), Vembanthanni (125) and Erumamala (118) were the densest blocks.

Elsewhere in Kerala the estimate is simply the highest count of the four days, topped up by camera traps left out for 20 to 30 days at isolated sites. That gave 524 animals outside Eravikulam, of which 285 were in the rest of the Munnar cluster of forest divisions and 96 in the Parambikulam cluster. Adding Eravikulam gives Kerala’s 1,365.

Tamil Nadu used a double-observer count, in which two people count independently and the overlap shows how many animals were missed. It estimated 282 in Mukurthi National Park, 334 in Grass Hills National Park and 687 in scattered smaller habitats, 1,303 in all, each with a stated confidence range.

A sanctuary notified because of shooting

The Government of Kerala declared the Eravikulam-Rajamally Sanctuary by a notification dated 31 March 1975, published in the Kerala Gazette of 8 April 1975. The explanatory note says the Chief Conservator of Forests had asked for it on the Wildlife Board’s recommendation, to protect wildlife and “especially the Nilgiri Tahr, a rare animal vanishing at an alarming rate due to indiscriminate shooting by people”. Requests for the declaration came from several quarters, including the Government of India.

It became a national park in 1978, the Kerala Forest Department says. Within about 97 sq km in the Kannan Devan Hills, the park takes in Anamudi, at 2,695 m the highest peak in South India. Eravikulam is one of the components of the Western Ghats World Heritage property, which our piece on the Western Ghats listing describes.

Counts at one park since 1969

WWF-India’s 2015 report collects the earlier numbers for Eravikulam. George Schaller counted about 439 tahr in 1969 and put the population at around 500. In 1978 Davidar estimated 650, and Rice’s estimates in the 1980s were about 550. A study by Abraham and colleagues gave 696 in April 2000, 559 in October 2000 and 444 in December 2001. WWF’s own table lists 700 as a census figure for the park in 2015, and the Kerala Forest Department’s 2017 survey also reported over 700.

WWF’s report cautions that these early studies used no standard protocol, so the figures are not a clean time series. Officials told Onmanorama that the 841 includes 144 newborns.

Fire, grass and a flower that returns every 12 years

Tahr prefer the fresh shoots that grow after a grass fire, and Eravikulam is managed with that in mind. According to the Kerala report, the animals move in a predictable way towards freshly burnt patches. It puts the zero counts that some blocks logged on the last days down to poor detection, wild dogs or herds moving to burnt ground. Officials told South First that the park burns grassland on a three-year cycle modelled on the practice of the Muthuvan tribe.

The same slopes carry neelakurinji (Strobilanthes kunthiana), a shrub that flowers across the hillsides about once every 12 years. Kerala’s forest department gives 2018 as the last bloom, and Kerala Tourism says the next is expected in 2030. Down To Earth lists the recorded bloom years from 1838 to 2018 in steps of 12, and says honey bees pollinate the flowers.

Tamil Nadu’s five-year project

On 28 December 2022 the government of Tamil Nadu ordered a dedicated project for the tahr, which is the state animal. It was set at Rs 25.14 crore (about Rs 251 million) over five years, 2022 to 2027, according to the wire report carried by ThePrint. State officials described it as the first project of its kind in the country.

The order provides for synchronised surveys using radio collars, restoration of fragmented habitat with shola grasslands as the priority, reintroduction to places where the tahr once lived, and tahr-based tourism. Shola grassland is the mix of high open grass and small patches of dense forest where the tahr feeds. The same order made 7 October Nilgiri Tahr Day, which PTI reports is the birth anniversary of the researcher E. R. C. Davidar. The project office is in Coimbatore.

The first synchronised survey ran from 29 April to 1 May 2024 with 708 people and covered 1,862 km on foot, the project’s own page says. It used drones for the first time to monitor inaccessible areas and gathered DNA samples for a genetic repository. A second, from 24 to 27 April 2025, involved 780 people. Its reported finds include a direct sighting at Chinnattumalai in Coimbatore division after a decade, dry droppings at Mangaladevi in Megamalai where the tahr had been thought to be gone, and a first-ever sighting at Peyar Varaiyattumottai in the Nellai Wildlife Sanctuary. The project’s page credits habitat restoration and control of invasive wattle, and names reintroduction and better links between isolated groups as the next steps. ThePrint’s account of the 2024 survey names Glenmorgan in the Nilgiris as one reintroduction site.

Two populations on either side of the Palghat gap

A 2018 paper by Wildlife Institute of India researchers in Mitochondrial DNA Part B sequenced 26 samples collected as droppings in Mukurthi National Park, north of the Palghat gap, and in the Anamalai Tiger Reserve, south of it. The tahr split into two clearly separate genetic groups, one on each side, and the authors estimate that the two lines diverged about 1.46 million years ago. They recommend managing the two as separate units and say more work is needed to measure how far they differ.

What the counts leave open

WWF-India’s 2015 report estimated 3,122 tahr across the whole range, and said good planning could support about 5,000. The 2025 total is 2,668. Different methods produced the two figures, and the Kerala report does not compare them. It says studies indicate a relatively stable trend in Kerala, where its statewide figure was about 1,420 in the 2016 survey and is 1,365 now.

Kerala’s report adds that no tahr were sighted in Vazhachal, Periyar East or Ranni, which may mean local extinction or may reflect gaps in survey effort and bad weather. Tamil Nadu’s intervals are wide: Grass Hills is 334 with a range of 135 to 640, and the scattered habitats are 687 with 508 to 1,347. How India counts its tigers and lions and the snow leopard assessment describe other national counts that also work with ranges.

The two governments’ tallies also differ slightly. Kerala’s report gives 1,365 for Kerala and 2,668 in total, while the Tamil Nadu project’s page gives 1,352 for Kerala and 2,655 in total, and neither explains the gap. The Kerala summary says about 90 percent of the state’s tahr are in the Munnar cluster, but its own tables give 1,126 for Munnar alone and 1,222, about 90 percent, only when Parambikulam is added.

Kerala’s department lists habitat loss, plantations, invasive plants, livestock grazing, roads, poaching and climate change as the threats. It recommends interim surveys at sites such as Neyyar Wildlife Sanctuary, identifying places to restock, and exploring reintroduction, and in the longer term regular, institutionalised monitoring.

Seeing the tahr at Rajamalai

Rajamalai is the only part of the park open to visitors, Kerala Tourism says, and the tahr can be seen there. Published hours differ, from 7 am to 6 pm on the Kerala Tourism fact file to 8 am to 4 pm in a March 2026 Onmanorama report, so the Munnar Wildlife Division is the place to confirm them. The park closes each February and March for the calving season, and in 2026 it reopened on 1 April, Onmanorama reported.