Question
What is the Red Data Book? How are species categorised in it? Give examples of species in different categories.
Solution — Step by Step
The Red Data Book (now Red List) is a catalogue maintained by the International Union for Conservation of Nature (IUCN), founded in 1963.
It documents the conservation status of species — animals, plants, and fungi — worldwide, based on quantitative criteria assessing extinction risk. It is the world’s most comprehensive inventory of threatened species and serves as a scientific basis for conservation policy and action.
India maintains its own Red Data Book for species found in the country.
The IUCN uses nine categories based on population size, rate of decline, geographic range, and probability of extinction:
| Category | Code | Description |
|---|---|---|
| Extinct (EX) | EX | No remaining individuals anywhere |
| Extinct in the Wild (EW) | EW | Survives only in captivity/cultivation |
| Critically Endangered (CR) | CR | Extremely high risk of extinction in wild |
| Endangered (EN) | EN | Very high risk of extinction in wild |
| Vulnerable (VU) | VU | High risk of extinction in wild |
| Near Threatened (NT) | NT | Close to qualifying for threatened status |
| Least Concern (LC) | LC | Widespread and abundant — not threatened |
| Data Deficient (DD) | DD | Insufficient information to assess |
| Not Evaluated (NE) | NE | Not yet assessed against criteria |
Critically Endangered:
- Amur Leopard (fewer than 100 in wild)
- Javan Rhinoceros
- Vaquita (porpoise — only a few individuals remain)
- In India: Indian Wild Ass has recovered but remains vulnerable
Endangered:
- Tiger (Panthera tigris)
- Asian Elephant
- Snow Leopard
- Giant Panda (recently downlisted to Vulnerable)
Vulnerable:
- Hippopotamus
- Polar Bear
- Whale Shark
- In India: Indian Lion (Asiatic Lion, Gir forest)
Extinct:
- Dodo (extinct since ~1680s)
- Passenger Pigeon (last one died 1914)
- Pyrenean Ibex (2000)
- Cheetah in India (local extinction 1952)
The IUCN uses five criteria (A-E):
- Criterion A: Rate of population decline (over 10 years or 3 generations)
- Criterion B: Geographic range size (extent of occurrence < 100 km² for CR)
- Criterion C: Population size < 250 mature individuals for CR
- Criterion D: Population size < 50 individuals for CR
- Criterion E: Quantitative analysis showing probability of extinction within 10 years > 50% for CR
Why This Works
Categorisation is based on quantitative, evidence-based thresholds rather than arbitrary judgements. This allows consistent global comparison and helps prioritize conservation funding and effort toward the most at-risk species.
The Red List is the scientific foundation for CITES (Convention on International Trade in Endangered Species) listings and national wildlife protection laws.
Common Mistake
Students sometimes write “Red Data Book is maintained by WWF.” This is incorrect — it is maintained by the IUCN (International Union for Conservation of Nature). WWF (World Wide Fund for Nature) is a separate conservation organization that uses IUCN data but does not compile the Red List itself.