Wildlife · Long read · 13 min read

The Nilgiri Tahr: Cliff Goat of the High Ranges

Is it a deer, a goat, or a missing link between the two? The science of Eravikulam's famous mountain ungulate: its true relatives, its ancient lineage, its life on the cliffs and its comeback.

By GK Global, Adimali, Munnar · Trails & Tales by GK

Drive up to Rajamala on a clear morning and you will meet them almost at once: sturdy, grey-brown animals grazing on the grass beside the road, with a stocky dark male standing guard on a rock above. These are Nilgiri tahr, the most famous residents of Eravikulam National Park, and one of the rarest large mammals in India. Local people call them varayadu in Malayalam and varaiaadu in Tamil, both meaning "cliff goat". Visitors often ask what exactly they are. Some guides even describe them as a "missing link" between a deer and a goat. The real story, told by modern genetics, is more surprising.

A missing link between deer and goat? No.

The idea is easy to understand. Females and young tahr are slim, brownish and alert, a little like deer, while the males look like heavy wild goats. But in biology the claim does not hold up, for three reasons:

1. Deer and tahr belong to different families. Deer are Cervidae. Tahr, goats, sheep and cattle are Bovidae. The two families separated many millions of years ago, long before any goat or deer of today existed. There is no living animal "between" them, and the tahr is firmly on the bovid side.
2. Horns, not antlers. Deer grow bony antlers that they shed and regrow every year, usually only in males. Tahr have true horns: a bony core covered in keratin, never shed, carried by both sexes, and growing throughout life. That is a goat-and-sheep trait, not a deer trait.
3. The genes point to sheep. The decisive evidence came in 2005, when the biologists Alexandre Ropiquet and Alexandre Hassanin compared the DNA of the world's three "tahrs". The Himalayan tahr and the Arabian tahr turned out to be close to the true goats (Capra). The Nilgiri tahr did not belong with them at all. Its closest relative was the sheep genus Ovis. It was moved into a genus of its own, Nilgiritragus, the "goat of the Nilgiris".

So the Nilgiri tahr is not a link between a deer and a goat. It is a sheep-related caprine that evolved to look and live like a goat. Most likely the deer comparison comes from appearance and from old local names: British planters in the High Range even called the tahr "ibex", while the name "jungle sheep" was used for the barking deer, a true deer.

Origin and evolution

An ancient, separate lineage

Based on the 2005 genetic study, the line leading to the Nilgiri tahr split from the line leading to modern sheep roughly 2.7 to 5.2 million years ago, in the Pliocene epoch. That makes the Nilgiri tahr the only living member of a lineage several million years old, found nowhere in the world except the southern Western Ghats.

Why three unrelated animals are all called "tahr"

For more than a century the Nilgiri, Himalayan and Arabian tahrs were grouped together because they look alike: stocky bodies, short backward-curving horns, and a life spent on steep rock. Genetics showed that the likeness is convergent evolution. Different lineages living on cliffs came to share the same practical design: short, strong legs, rubbery hooves that grip rock, and compact horns that don't snag on ledges.

Did it migrate from the Himalaya?

This is often said, but there is no scientific evidence for it. The Himalayan tahr belongs to a different branch of the family, close to the goats, so the Nilgiri tahr is not a Himalayan tahr that wandered south. How and when its ancestors first reached the Western Ghats is still an open question. No fossil record of the lineage has been described, and the genetic studies only tell us when it split from its relatives, not where its ancestors lived.

Two populations divided by a gap

Within the Western Ghats, genetics tells a clearer story. A 2018 study of tahr DNA from both sides of the Palghat Gap, the 40 km-wide break in the mountains between the Nilgiris and the Anamalai–Munnar hills, found two slightly different populations. The difference is shallow. The authors suggest the populations separated during climate changes of the Pleistocene (the last 2.6 million years, the age of the ice ages), when suitable cool grassland probably once linked the two sides. The Eravikulam tahr belong to the southern group. The study used only a small number of samples, so this picture may be refined.

Built for the cliffs

Adult males are large, stocky and dark brown to almost black, with a pale, silvery-grey patch across the back that gives them the name "saddlebacks". Females and young are greyer and lighter. Both sexes carry short horns that curve backwards, thicker and longer in males. Tahr live on the high grasslands next to rocky cliffs: they graze in the open and retreat to the cliffs to rest, find shade at midday and escape predators. They avoid the lower forests.

A day in the life

Tahr are grazers. In one detailed study in the Nilgiris, grasses made up about 64% of their diet, with a handful of plant species making up most of what they ate. Browsing on shrubs and leaves is rare. Their day alternates between grazing and resting, mostly in the cool hours, with long rests in the shade of the rocks.

They live in herds, typically of females, young and juveniles, with adult males joining and leaving. Herd sizes vary widely; one study at Eravikulam recorded an average of about 42 animals. Females keep to particular home ranges, while adult males move between groups. At least one animal, usually an adult female, acts as a sentinel, and at any sign of danger she gives a sharp whistle or snort that sends the herd towards the cliffs.

Their main natural predators are the leopard and the dhole (wild dog), with the tiger taking some. In a study in the Nilgiris, tahr made up more than half the leopards' diet.

The life cycle

• RutThe mating season peaks during the south-west monsoon, roughly June to August, although mating has been reported in other months. Saddleback males move among the female herds and compete for mates.
• GestationAbout six months (roughly 178–190 days).
• BirthMost kids are born in January and February. A female usually has a single kid, very rarely twins. This is why Eravikulam National Park closes to visitors for several weeks each year, usually around February–March: the calving season.
• First weeksNewborn kids stay hidden among rocks and grass for their first weeks, then follow their mothers in the herd.
• WeaningKids are weaned at about 4–6 months.
• MaturityFemales can breed from about 16 months. Males take much longer: their pale saddle develops gradually over several years, and they reach full size and social standing at around 6–8 years.
• LifespanWild tahr have been recorded living to about 9 years. Because many kids and young animals are lost to predators, disease and harsh weather, the average lifespan is much shorter.

Back from the brink

The Nilgiri tahr once roamed much of the high Western Ghats. Hunting in the 19th and early 20th centuries, and the conversion of grassland into tea, plantations of wattle, eucalyptus and pine, and reservoirs, reduced it to scattered patches. It has disappeared from a significant part of its old shola–grassland habitat.

Eravikulam's role in its survival began with the planters themselves. In 1928 the estate managers of the High Range formed a game association to regulate hunting, and employed Muthuvan tribesmen as game guards. The Kannan Devan company ran the plateau as a game reserve until 1971, when it passed to the Kerala Forest Department. Eravikulam was declared a sanctuary in 1975, mainly to protect the tahr, and a national park in 1978. In 1975 the naturalist E. R. C. Davidar carried out one of the first studies of the species; Tamil Nadu now marks 7 October, his birthday, as Nilgiri Tahr Day.

Protection worked. Eravikulam's population was counted at about 640 in 1996, and at 841 in the first joint Kerala–Tamil Nadu census in 2025, which found 2,668 tahr in all (1,365 in Kerala and 1,303 in Tamil Nadu). Other estimates put the total a little higher. Tamil Nadu launched India's first dedicated Project Nilgiri Tahr (2022–2027, about ₹25 crore) for surveys, radio-collaring, reintroduction to former haunts and grassland restoration.

Seeing tahr at Eravikulam

The Rajamala section of Eravikulam National Park, reached by forest department bus from the Fifth Mile entry near Munnar, is one of the easiest places in the world to see a wild endangered mountain ungulate up close. The tahr here are used to people and often graze within metres of the path.

• Never feed or touch the tahr. Human food makes them sick and dependent, and they are wild animals with sharp horns.
• Go early for cooler weather, clearer views and active herds.
• Check the dates: the park usually closes for several weeks around February–March for the calving season.
• Look up at the cliffs as well as beside the road. The big saddlebacks often keep watch from the rocks.

Read more about the park and its other wildlife in our wildlife guide and sightseeing guide.

Not a deer, not quite a goat, and only distantly a sheep: the Nilgiri tahr is something found nowhere else on Earth, and Eravikulam is its last great stronghold.