Smew

Why in News?

Recently, the 7th waterbird census at Kaziranga National Park and Tiger Reserve recorded the first-ever sighting of the smew, raising concerns about climate-driven range shifts.

• Scientific Name – Mergellus albellus
• It is commonly known as the Eurasian Diving Duck.
• Family – Anatidae (duck, goose and swan family).
• Habitat – Freshwater wetlands, lakes, slow-moving rivers, floodplain beels.
• It prefers fish-rich, sheltered waters during winter.
• Distribution – Eurasian taiga (northern Europe & Siberia) and a winter migrant to parts of Europe and Asia.
  • In India – A rare winter visitor with sporadic sightings in northern and central wetlands such as Haiderpur (Uttar Pradesh) and Corbett.
• Key Identification – Small, striking diving duck.
  • Male – Distinct black mask on a white body (“white nun” appearance).
  • Female – Mottled grey-brown body with chestnut head and white throat.
• Behaviour & Diet – Usually seen in small flocks.
• Feeds mainly on small fish and aquatic invertebrates.
• Breeding -Breeds in taiga forest regions with tree cavities.
• Conservation Status –
  • IUCN – Least Concern
• Threats – Habitat loss and wetland degradation, climate-driven range shifts, hunting pressure, and oil pollution.

7^th Kaziranga Waterbird Census

• Survey – Spanned 166 wetlands across 10 ranges of the Kaziranga Tiger Reserve.
• Abundant species – The bar-headed goose, northern pintail, and lesser whistling duck.
• Ecological Significance – Reaffirms Kaziranga as a critical wintering ground on the Central Asian Flyway

Ramsar Criterion 5 stipulates that a wetland is considered internationally important if it regularly supports 20,000 or more waterbirds.

• Top Wetlands By Population (Count) –
  • Rowmari Beel (Laokhowa) – 15,661
  • Donduwa Beel – 14,469
  • Katakhal – 4,979
  • Sohola – 3,612
  • Khalihamari – 3,463
• Top Wetlands By Diversity (Species) –
  • Rowmari Beel – 77 species
  • Donduwa Beel – 71 species
  • Sohola – 69 species
  • Kawoimari-Bhoisamari-Diffulo – 57 species
  • Ververy – 53 species

References

1. TH | Smew Sighting in Kaziranga Raises Climate Concern
2. ToI | Smew