Every year, at least one question on biodiversity hotspots quietly appears in the UPSC Prelims paper — and every year, thousands of aspirants get it wrong because they memorised names but missed the details. After teaching environment for over a decade, I can tell you that the examiner loves testing the criteria, the numbers, and the less-obvious connections in this topic.
This piece will walk you through everything you need — from the basic definition to the specific facts that UPSC keeps returning to. Whether you are starting your preparation or revising before the 2026 Prelims, this will serve as a reliable one-stop resource.
Where This Topic Sits in the UPSC Syllabus
Biodiversity hotspots fall squarely under the Environment and Ecology segment. For Prelims, they appear under General Studies Paper I. For Mains, they connect to GS-III under the conservation and environmental pollution section. The topic has appeared directly or indirectly in Prelims at least 8 to 10 times in the last 15 years.
| Exam Stage | Paper | Syllabus Section |
|---|---|---|
| Prelims | General Studies | Biodiversity and Environment |
| Mains | GS-III | Conservation, Environmental Pollution and Degradation |
Related topics that often get clubbed with this include endemism, IUCN Red List, protected areas, and international conventions like the Convention on Biological Diversity (CBD).
What Exactly Is a Biodiversity Hotspot?
The concept was first introduced by British ecologist Norman Myers in 1988. He identified 10 tropical forest areas that had exceptional plant endemism and were facing serious habitat loss. The idea was simple — focus conservation efforts where they matter most.
Later, Conservation International adopted and expanded the concept. Today, the globally accepted definition requires a region to meet two strict criteria simultaneously. First, it must contain at least 1,500 species of vascular plants as endemics — meaning those species are found nowhere else on Earth. Second, it must have lost at least 70% of its primary native vegetation.
This second criterion is what makes a hotspot different from a region that is simply biodiverse. The Amazon rainforest, for instance, is extraordinarily rich in species but retains much of its original vegetation. So it is not classified as a hotspot. UPSC has tested this distinction before, and I expect it will again.
The Global Count and Why It Keeps Changing
As of 2026, there are 36 recognised biodiversity hotspots worldwide. This number has grown over the decades. Myers originally identified 10 in 1988, which expanded to 25 by the year 2000. Subsequent revisions brought the count to 34, then 35, and now 36. The most recent addition was the Forests of East Australia.
These 36 hotspots together cover only about 2.5% of Earth’s land surface but support more than 50% of the world’s plant species and roughly 43% of bird, mammal, reptile, and amphibian species as endemics. This contrast between tiny area and massive biodiversity is the core reason why hotspots receive so much conservation attention.
UPSC loves to test these numbers. I have seen questions where options differ only by small percentages. So fix these figures in your memory: 36 hotspots, 2.5% land area, over 50% endemic plants.
India’s Four Biodiversity Hotspots
India is one of the few countries with multiple hotspots within its borders. There are four, and each one has specific details the examiner targets.
The Western Ghats — This mountain range running along India’s western coast from Gujarat to Tamil Nadu is one of the most studied hotspots globally. It harbours over 5,000 flowering plant species, of which about 1,700 are endemic. The Nilgiri Tahr and the Lion-tailed Macaque are flagship endemic species. The Western Ghats were also designated a UNESCO World Heritage Site in 2012. The Kasturirangan Committee Report on Western Ghats conservation is a connected topic that appears in Mains.
The Eastern Himalayas — Covering parts of northeast India, Nepal, Bhutan, and southern China, this hotspot is home to iconic species like the Red Panda and the Golden Langur. The region’s extreme altitudinal variation — from tropical plains to alpine meadows — creates extraordinary ecological diversity. UPSC sometimes asks whether the entire Himalayan range is a hotspot. The answer is no. Only the eastern part qualifies.
Indo-Burma Region — This hotspot extends across northeast India into Myanmar, Thailand, Vietnam, and surrounding areas. It includes parts of Manipur, Mizoram, and Nagaland. The region has high freshwater fish diversity and is a centre of origin for cultivated rice varieties. Many aspirants confuse this with the Eastern Himalayas, but they are distinct hotspots with different geographical boundaries.
Sundaland — This includes the Nicobar Islands from India’s territory, along with parts of Malaysia, Indonesia, and the Philippines. Many students forget that India has a stake in this hotspot. The Nicobar Islands host unique fauna like the Nicobar Megapode. If a question asks how many hotspots India has — the answer is four, not two or three.
The Facts UPSC Keeps Testing
From my analysis of previous year papers and mock tests set by credible sources, certain patterns emerge clearly. Here are the factual areas the examiner returns to repeatedly.
Criteria confusion: Questions often include wrong criteria in the options — such as requiring 500 endemic species instead of 1,500, or 50% vegetation loss instead of 70%. Always remember both thresholds precisely.
India’s hotspot count: The number four trips up many aspirants. Some forget Sundaland. Others think the Thar Desert or the Gangetic plains qualify. They do not.
Hotspot versus mega-diverse country: India is both a mega-diverse country (one of 17 globally) and a country with biodiversity hotspots. These are different classifications. UPSC has mixed these in options to confuse test-takers.
Species endemism over species richness: A hotspot is defined by endemic species under threat, not merely by total number of species. This subtle distinction has appeared in analytical Mains questions.
Overlap with protected areas: Several national parks and wildlife sanctuaries sit inside hotspot boundaries. Silent Valley, Periyar, and Namdapha are examples. Questions sometimes link protected area knowledge with hotspot identification.
Connecting Hotspots to Other UPSC Topics
This topic does not exist in isolation. For Mains, you should be able to connect biodiversity hotspots to climate change impacts, tribal rights in ecologically sensitive areas, and India’s obligations under the CBD and the Kunming-Montreal Global Biodiversity Framework adopted in 2022. The framework’s target of protecting 30% of land and ocean by 2030 — the 30×30 target — links directly to hotspot conservation.
For Ethics (GS-IV), you can use biodiversity hotspots as examples when discussing environmental ethics, intergenerational equity, or the conflict between development and conservation. The Gadgil Committee versus Kasturirangan Committee debate on the Western Ghats is excellent case material.
Key Points to Remember for UPSC
- Norman Myers coined the biodiversity hotspot concept in 1988; Conservation International later expanded it to 36 hotspots globally.
- Two mandatory criteria: at least 1,500 endemic vascular plant species and at least 70% loss of original habitat.
- All 36 hotspots cover just 2.5% of Earth’s land but hold over 50% of endemic plant species worldwide.
- India has four hotspots: Western Ghats, Eastern Himalayas, Indo-Burma, and Sundaland (Nicobar Islands).
- The Amazon is mega-biodiverse but not a hotspot — it has not lost 70% of its vegetation.
- India is both a mega-diverse country and a biodiversity hotspot country — these are separate classifications.
- The 30×30 target under the Kunming-Montreal Framework directly relates to hotspot conservation strategy.
- The Kasturirangan Committee Report on the Western Ghats is a frequently tested linked topic in Mains.
Biodiversity hotspots are one of those rare UPSC topics where knowing precise numbers and clear definitions gives you a direct scoring advantage. I would suggest making a one-page comparison chart of all four Indian hotspots — their location, key endemic species, and linked government committees or reports. Pin it where you study. When this topic appears in your 2026 paper, and it very likely will, you want the facts to come to you instantly.