Western Ghats Odonata Survey: 143 Species, 35% Shortfall
Why in the news
A field survey of dragonflies and damselflies (Odonata) in the Western Ghats could trace only about 65% of the species reported in the past. That points to a possible 35% loss in diversity of a group that signals the health of freshwater habitats.
Key facts
- Lead researcher: Dr. Pankaj Koparde, Assistant Professor, MIT-World Peace University, Pune.
- Coverage: 144 sites in Maharashtra, Kerala, Karnataka, Goa and Gujarat; period: February 2021 to March 2023.
- Species found: 143, made up of 76 dragonflies and 67 damselflies; 40 are endemic.
- Main finding: about 65% of historically known species recovered, implying a 35% shortfall.
- Endemism is higher in the Southern Western Ghats, especially Kerala south of Coorg, thanks to perennial streams and richer microhabitats.
| State | Sites | Species | Endemics |
|---|---|---|---|
| Maharashtra | 105 | 100 | 12 |
| Kerala | 14 | – | 33 (highest) |
| Karnataka | 17 | 64 | 6 |
| Goa | 3 | 35 | 4 |
| Gujarat | 5 | 18 | 0 |
IUCN Red List status of the 143 species
| Status | Count / species |
|---|---|
| Least Concern | 100 |
| Data Deficient | 22 |
| Not Evaluated | 16 |
| Near Threatened | 2 – Phylloneura westermanni, Heliogomphus promela |
| Vulnerable | 3 – Elattoneura souteri, Protosticta sanguinostigma, Cyclogomphus ypsilon |
The 22 Data Deficient species show that too little is known to even judge their status, so more surveys are needed.
Threats and recommendation
- Threats listed: linear infrastructure, hydropower projects, pollution, land-use change, unregulated tourism, forest fires and climate change.
- Recommendation: more intensive and systematic surveys in unexplored and under-sampled parts of the Western Ghats.
Background
- Odonata is an order of carnivorous insects: dragonflies (suborder Anisoptera) and damselflies (suborder Zygoptera), with aquatic larvae called nymphs.
- Dragonflies are bigger and rest with wings open or flat; damselflies are slender and fold their wings along the body.
- They are indicator taxa because they depend on clean freshwater and react to changes in water quality, temperature and habitat.
- The Western Ghats: a 1,600-km chain through Gujarat, Maharashtra, Goa, Karnataka, Kerala and Tamil Nadu; one of eight ‘hottest’ biodiversity hotspots; UNESCO World Heritage Site since 2012 (39 serial sites).
- Gadgil Committee (2011) proposed protecting about 64% of the Ghats as ecologically sensitive; Kasturirangan Committee (2013) cut it to about 37%.
- IUCN categories, most to least threatened: Extinct, Extinct in the Wild, Critically Endangered, Endangered, Vulnerable, Near Threatened, Least Concern; Data Deficient and Not Evaluated sit outside the ranking.
Exam angle
- Odonata = dragonflies plus damselflies; indicator of freshwater health.
- Endemic hotspot within the survey: Kerala (33 endemic species).
- Terms: endemism, indicator species, Data Deficient, hotspot criteria of high endemism and major habitat loss.