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.

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

Every winter, hundreds of colossal, leathery-shelled reptiles arrive at Galathea Bay on Great Nicobar Island. They dig deep trenches, lay their eggs, and cover them with sand before heading back into the waters. In around two months, the eggs begin to hatch, and baby turtles take their first steps and head into the ocean, as their ancestors have for millions of years. But now, a large trans-shipment port, planned as part of the Great Nicobar Island project, could threaten the turtle’s survival on this beach.

The leatherback turtle (Dermochelys coriacea) is the largest of all living sea turtles and is the only one without a hard shell. It instead has a leather-like, flexible carapace that allows it to dive deeper (up to 1,000 metres) than other turtles. Adults can grow nearly two metres long and weigh as much as a compact car (1,000 kilograms). The turtles feeds almost entirely on jellyfish, helping keep their populations in check and maintaining ecosystem balance.

Leatherbacks are found in every ocean except the Arctic and Antarctic and spend most of their lives in open waters. The females of the species migrate thousands of kilometres from foraging grounds to nest on open sandy beaches in tropical and subtropical countries. In India, they nest almost exclusively in the Andaman and Nicobar Islands, with Galathea Bay being the largest nesting ground in the northern Indian Ocean. Other major global nesting spots are located in Gabon, Trinidad and Tobago, Suriname, Costa Rica, Indonesia, Papua New Guinea, and Mexico.

The IUCN lists the leatherback turtle as globally vulnerable due to declining populations. In India, it has the highest legal protection under Schedule I of the Wildlife (Protection) Act, 1972, offering it the highest protection from hunting, poaching and trading.

Loss of nesting sites, due to development activities and beach erosion, is one of the key threats to the turtles’ survival. They also get caught as bycatch in fishing operations, collide with boats and ingest plastic waste. Artificial lighting near nesting beaches also deters adult females from nesting and also disorients the baby turtles. Particularly in Nicobar, the ₹81,000 crore (₹810 billion) trans-shipment project includes building an international container port on the leatherback turtle nesting site, as well as an airport, gas and solar power plant, and township which will lead to the felling of a million trees.

Read more about the leatherback turtle conservation in the Little Andamans, environmental clearances surrounding the Great Nicobar project, and how turtles adapt to climate change.

Banner image: A juvenile leatherback turtle. Image by Ken Clifton via Flickr (CC BY-NC 2.0).

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

In the forests of northeast India, a series of whoops and hoots rises through the canopy in a melodious crescendo every morning — the unmistakable song of the western hoolock gibbon. Pairs often duet to mark their territory, reinforce pair bonds and communicate with their family members.

The western hoolock gibbon (Hoolock hoolock) is India’s only ape. While adult males have a fully black coat, females are buff to golden-brown. Exclusively arboreal, which means they spend their lives on trees, they use their long arms to swing between branches with ease. They feed primarily on fruits, and occasionally leaves and insects, making them vital for seed dispersal and forest regeneration.

In India, the species is found in the tropical and subtropical forests of the northeast, across Assam, Arunachal Pradesh, Meghalaya, Manipur, Mizoram, Nagaland, and Tripura, with populations extending into Bangladesh, Myanmar, and perhaps southern Tibet. Two other hoolock gibbon species — the eastern hoolock gibbon (Hoolock leuconedys) and the Gaoligong hoolock gibbon (Hoolock tianxing) — are found in Myanmar and China.

An estimated 90% of the global hoolock gibbon population has been lost over the past three decades. Around 3,000 western hoolock gibbons are believed to remain; 2,600 of them in India. According to the IUCN Red List, the western hoolock gibbon is listed as endangered, as is the Gaoligong hoolock gibbon; the eastern hoolock gibbon is listed as vulnerable. The species receives the highest level of legal protection in India, under Schedule I of the Wildlife (Protection) Act, 1972.

Hoolock gibbons require contiguous, closed-canopy forests for survival, and are thus highly vulnerable to habitat loss and fragmentation. The loss of even a single connecting tree can render fragments unreachable. Hunting and the illegal pet trade compound the pressure.

In an earlier story published by Mongabay-India in 2019, primatologist Narayan Sharma, Cotton University, Assam, said: “When a contiguous habitat is reduced to scattered smaller fragments, they become ‘habitat islands’ in an inhospitable sea of degraded habitat. This could result in inbreeding. The resultant offspring are often weak, sometimes sterile or may have little reproductive fitness.”

Read more about the hoolock gibbon in our stories on saving India’s only ape, community conservation efforts, and how tree bridges could help connect fragments.

Banner image: A western hoolock gibbon in Namdapha Tiger Reserve. While adult males have a fully black coat, females are buff to golden-brown. Image by Rohit Naniwadekar via Wikimedia Commons (CC BY-SA 4.0).