Species File: Exploring India’s biodiversity, one species at a time.

A 2026 survey counted 1,364 Nilgiri tahr in Tamil Nadu, nearly 5% more than the last year. Southern India’s only mountain ungulate, the Nilgiri tahr (Nilgiritragus hylocrius), is Tamil Nadu’s state animal.

Endemic to the Nilgiris, it is locally known as varayaadu, or cliff goat. A stout animal with curved horns and strong hooves with rubber-like soles, it scales sheer vertical cliffs with ease — a skill that helps it evade predators and access nooks which larger herbivores cannot. Tahrs graze on grass and shrubs, spreading seeds and fertilising the soil with their excreta as they go.

The Nilgiri tahr lives in the high-altitude grasslands and rocky cliffs in the southern Western Ghats. Eravikulam National Park in Kerala holds the largest population. In Tamil Nadu, the two largest contiguous habitats are in Grass Hills National Park in the Anamalai Tiger Reserve and Mukurthi National Park in the Nilgiris.

It is listed as endangered on the IUCN Red List and in  India, it has the highest legal protection under Schedule I of the Wildlife (Protection) Act, 1972, offering it the strongest protection against hunting, poaching, and trading.

But its range has shrunk to a fraction of what it once was, largely due to agricultural plantations, hydroelectric and infrastructure projects, and invasive plants that have eaten into its grassland habitat. Studies show that a warming climate could render much of the Nilgiri tahr’s remaining habitat unsuitable in the coming years. Isolated populations face the added risks of inbreeding and disease transmission from stray dogs.

In a story published by Mongabay-India in 2024, M.G. Ganesan, director of Project Nilgiri Tahr,  said: “The Nilgiri tahr lives 300 to 2,800 metres above mean sea level. Due to anthropogenic reasons and climate change, its elevation has been increasing, making manual surveillance and population counting methods impossible.”

Read more about the Nilgiri tahr in our stories on how Eravikulam became a refuge for the tahr, climate change threats to its habitat, and how drones are helping monitor the species.

Banner image: A Nilgiri tahr. Image by Kalyan Varma via Wikimedia Commons (CC BY-SA 4.0).

The gender of elected representatives can influence forest-cover growth, indicates a study that examines the causal impact of female elected representatives on forest conservation in India. The study concludes that electing a female MLA increased annual forest-cover growth by about six percentage points in constituencies reserved for historically marginalised communities such as Scheduled Castes and Scheduled Tribes. The study titled Female legislators and forest conservation in India was published in the Journal of Economic Behavior & Organization early this year.

The authors adopted a regression discontinuity design (RDD) strategy, in which they compared forest-cover growth in constituencies where a female politician won with those where a male politician won in “close” mixed-gender electoral races.

“Closely contested state assembly elections reveal a clear pattern: where women narrowly win against male candidates, forest cover grows faster in subsequent years,” write the authors in a related article published in The Policy Edge. “In extremely close mixed-gender elections, the outcome is often shaped by small, contingent factors rather than systematic differences between constituencies. Comparing such razor-thin contests allows a credible estimate of the effect of legislator gender,” the article elaborates.

The researchers combined forest-cover data from 2000–2014, state assembly election data, information on the gender of the winning candidate, and details on whether the constituency was reserved for Scheduled Castes (SCs) or Scheduled Tribes (STs) to identify a pattern and arrive at this conclusion.

The researchers explore several possible explanations for the outcome through existing literature. They suggest that, in many cases where women are disproportionately affected by climate change impacts, women may have greater concern for environmental protection and climate change, while women from marginalised communities may have greater awareness of climate vulnerability. Moreover, since SC/ST-reserved constituencies already have legal and institutional provisions relating to forest rights and environmental governance, female representation may interact with these existing structures in ways that favour conservation.

“Individuals from marginalised communities often face the additional constraint of limited resources to adapt to environmental degradation and climate shocks. Female politicians from these communities may therefore be particularly aware of the challenges faced by women and girls in their constituencies. This awareness can translate into stronger emphasis on environmental conservation in their political priorities,” the authors write.

Age too could play a role, considering that the female legislators studied tended to be younger than male legislators, and the forest-cover effect over the electoral term was particularly apparent among younger women.

Banner image: Women walk after collecting firewood for their homes from a forest area in Lucknow, Uttar Pradesh. (AP Photo/Rajesh Kumar Singh)

Species File: Exploring India’s biodiversity, one species at a time.

A recent report from Arunachal Pradesh noted the surprising presence of an animal at the high altitude of 3,266 metres — the Indian elephant. This is possibly the highest confirmed presence of Asian elephants anywhere in the world.

The Indian elephant (Elephas maximus indicus), a subspecies of the Asian elephant, is the largest land mammal in the country. Compared to their African cousins, Asian elephants are smaller, with smaller ears and rounded backs, and typically only the males have prominent tusks.

Highly intelligent and social, elephants live in matriarchal herds where the oldest females often lead the way. They communicate through rumbles, roars, chirps and infrasonic calls that can travel for kilometres.

The Indian elephants typically live in tropical and subtropical forests, grasslands and scrublands. They need large, contiguous landscapes to roam, feed and breed. They disperse seeds, dig for water and clear vegetation, making them crucial ecosystem engineers.

Roughly 50,000 Asian elephants remain in the wild in 13 countries, including Nepal, Bhutan, Bangladesh, and parts of Southeast Asia, with India holding almost half, at an estimated 22,446, of the subspecies. They occupy fragmented forests across the northeastern, northern, central and southern regions of the country, with the Western Ghats holding the largest populations.

The IUCN Red List classifies the Asian elephant as endangered due to declining populations. In India, it receives the highest legal protection under Schedule I of the Wildlife (Protection) Act, 1972, and is listed in Appendix I of CITES, which bans international trade.

Habitat loss and fragmentation, driven by roads, railways, hydropower projects, mining, and expanding settlements, are forcing elephants into closer contact with agricultural lands and human settlements, increasing human-elephant conflict. Railway tracks cutting through forests are especially deadly: between 2018 and 2023, 75 elephant deaths in India were attributed to collisions with trains. Additionally, poaching and electrocutions due to illegal electric fences remain significant threats.

In a story published by Mongabay-India in July 2026, Aritra Kshettry, who works with WWF-India’s Elephant Conservation Programme (ECP), said, “Maintaining connectivity between habitats is crucial to reducing human-elephant conflict as fragmented landscapes can force elephants into human settlements, increasing the likelihood of conflict.”

Read more about the high-altitude elephants in Arunachal Pradesh, the science behind elephant communication, and possible measures to prevent elephant deaths on roads and rail tracks.

Banner image: A male Indian elephant in Bandipur National Park, Karnataka. Image by Yathin S Krishnappa via Wikimedia Commons (CC BY-SA 4.0).

Given the sowing data and the possibility of persistent El Niño conditions, the Department of Economic Affairs (DEA), in its monthly economic review released on August 31, said particular attention may be required for pulses, oilseeds, rice and other rainfall-sensitive crops in the months ahead.

As per the review, kharif sowing stood at 105.67 million hectares as on August 21, around 1.5% below the corresponding period of last year. The decline was concentrated particularly in paddy, maize and soybean, while pulses acreage was marginally higher than a year earlier.

The gap in sowing has narrowed since August 7, when kharif sowing stood at 96.79 million hectares, 1.8% below the corresponding period of last year. Paddy acreage then stood at 34.48 million hectares, compared with 36.07 million hectares a year earlier.

Although the deficit had narrowed from the much larger shortfall observed earlier in the season, India Meteorological Department’s assessment indicates that the all-India cumulative rainfall deficit remained at 13% as of August 19.

Persistent regional deficits remain relevant for crop prospects and rural incomes, the review added.

Although the report said the relationship between El Niño and agricultural outcomes is not one-to-one, it identified the evolution of El Niño as an important emerging risk. The latest INCOIS Special El Niño Outlook Bulletin confirms that El Niño conditions had developed over the central Pacific by July 2026 and assigns an 80-98% probability that El Niño will remain the dominant ENSO phase from August 2026 through March 2027. The persistence of El Niño raises the risk of a weaker or uneven monsoon and, consequently, of pressure on crop yields and food prices.

The latest update by IMD, India’s weather agency, on August 31 has said, “Monthly rainfall over the country as a whole during September 2026 is most likely to be below normal.” The IMD said strong El Niño conditions are currently prevailing over the equatorial Pacific and are expected to strengthen further in the coming months.

It also highlighted uncertainty about the Indian Ocean Dipole (IOD), which is currently neutral. A positive IOD can partly offset the adverse influence of El Niño on India’s monsoon rainfall.

India’s Monsoon Mission Coupled Forecast System expects neutral IOD conditions to persist through September. However, some international climate centres forecast a possible shift towards a positive IOD from September onward, the IMD said.

Banner image: The gap in sowing has narrowed, but persistent regional deficits remain relevant for crop prospects and rural incomes, according to the Department of Economic Affairs (DEA)’s latest review. Image by Kundan Pandey/Mongabay.

The Supreme Court ordered the Union Environment Ministry to conduct a fresh survey of India’s elephant corridors and report the reasons for obstructions within them by October 14. The Court made its order on August 17 while hearing a petition against the practice of using fireballs and other harmful methods to deter elephants from entering human dominated landscapes.

The Court observed that though guidelines existed to ensure the smooth passage of elephants, “owing to certain local factors, the elephant corridors have been impeded/blocked/obstructed.” Elephant corridors are strips of land that facilitate the movement of elephants between two or more viable habitat patches.

In his oral remarks, Chief Justice Surya Kant reportedly said that no state could obstruct such corridors. “Construction of any kind of obstacle or creating blockades in elephant corridors is not acceptable. We are very clear that there cannot be obstacles in the way of wildlife,” the three-judge Bench stated, as per media reports.

The Wildlife Institute of India identified 150 elephant corridors in the country in 2023. Most of these corridors fall outside protected areas and national parks, and are encroached by settlements, agriculture, fences, and other infrastructure projects. Out of the 150 corridors identified, 15 were found to be impaired, 29 were found to be used in decreasing frequency, and no information was available for another 18.

The Supreme Court instructed the Ministry to conduct a fresh survey and submit a comprehensive report “including the necessary steps taken by them to prevent such obstruction.” It also said the status report should include the progress on steps taken to prohibit the use of fireballs, mashaals (fire torches), or any other coercive measure to divert the natural movement of the elephants.

“A specific ban on ‘Hulla Parties’, etc. would also be required in this regard, and this Court shall be apprised about the action taken on the same through the aforesaid status report,” says the order. Hulla parties are groups of people who are tasked with scaring elephants away, often using spiked rods and fireballs. In West Bengal, these groups are recruited by the state government.

Elephants are a Schedule 1 species under the Wildlife (Protection) Act, afforded the highest protections under the law. A contempt plea was filed against the West Bengal government in 2024, after a pregnant female elephant was attacked by a hulla party. The elephant died after a fire-spiked rod pierced her back.

Banner image: A group of elephants crossing the Nepal-India border. Image by Nissan Sharma via Wikimedia Commons [CC BY-SA 4.0].

A new study finds that closely-related Western Ghats frogs living together tend to differ in body size, suggesting that competition and species sorting help determine which species can coexist.

Scientists at the Centre for Ecological Sciences, Indian Institute of Science, Bengaluru, examined body-size differences among species belonging to three frog genera in the Western Ghats: Nyctibatrachus and Micrixalus, which are endemic to the region, and Hylarana, which is more widely distributed. They also examined the frogs’ phylogenetic relationships, distribution and microhabitat use.

The scientists found that stream-dwelling frogs showed patterns of body-size assortment. This was especially evident in the endemic Nyctibatrachus and Micrixalus, where species occurring together were significantly more different in body size than would be expected by chance.

For example, among 27 three-species Nyctibatrachus assemblages, 23 contained species belonging to different body-size classes. Among the 19 two-species Micrixalus assemblages, every pair belonged to different size classes.

The paper’s first author, Kartik Shanker, says the pattern appears to have resulted from competition and “species sorting”, an ecological process in which competition can exclude species with similar traits from local communities while allowing more dissimilar species to coexist.

This pattern, however, was missing in Hylarana. “The two clades (Nyctibatrachus and Micrixalus) appear to have adapted early on in their evolution to streams and ponds, creating a separation,” Shanker says.

The size differences were particularly pronounced among species living in the same habitat. The study found that body-size differences between sympatric Nyctibatrachus species were greater than between species occurring in adjacent but separate areas.

The study also found an association between body size and microhabitat in Nyctibatrachus. Larger frogs tended to occupy faster-flowing sections of streams, while smaller species were more often found along stream edges, away from the strongest flow. Such differences could allow species to use different parts of the same stream and reduce competition.

“Larger bodies allow them to hold on to the rocks in the faster-flowing parts of the streams, smaller bodies allow them to hide in the leaf litter,” Shanker points out as an example of an ecological advantage of this pattern.

However, this relationship was not significant in Micrixalus or Hylarana, suggesting that other forms of ecological niche partitioning may be operating in those groups.

Importantly, the researchers did not find strong evidence that competition directly drove the evolution of body size. Shanker says: “We find that competition did not lead to evolutionary divergence. Thus, the pattern may have come about by species sorting, that is, after divergence into different species, thus more at an ecological than an evolutionary scale. But the driver is competition.”

The study therefore provides evidence that competition can structure biodiversity without necessarily driving adaptive evolution. A potential conservation implication, Shanker says, is that changes to microhabitats could threaten species even when the broader forest habitat remains the same.

Banner image: The Micrixalus kottigeharensis frog species. Image by Dhritiman Mukherjee.