Terek Sandpiper (Xenus cinereus) – A Detailed Study

Taxonomy & Classification

• Kingdom: Animalia
• Phylum: Chordata
• Class: Aves
• Order: Charadriiformes
• Family: Scolopacidae
• Genus: Xenus
• Species: Xenus cinereus

The Terek Sandpiper is the only species under the genus Xenus, making it a unique bird within the Scolopacidae family.

Morphology & Identification

• Size: Medium-sized wader, approximately 22–25 cm in length.
• Wingspan: Ranges between 43–47 cm.
• Weight: Averages 60–100 g.
• Beak: Slightly upturned, long, and slender, resembling that of an avocet.
• Legs: Yellowish to orange, relatively short for a wader.
• Plumage:
  • Upperparts are greyish-brown with fine streaks.
  • Underparts are pale white with a buff tinge on the breast.
  • Distinctive white wing bars visible in flight.
• Call: A sharp, repetitive “chip-chip” sound, especially during flight.

Habitat & Distribution

The Terek Sandpiper is a migratory shorebird, breeding in the northern Palearctic region, from Finland and Siberia to northeastern China. It winters along tropical coasts, including South Asia, Africa, and Australia.

• Breeding Habitat:
  • Prefers wet meadows, riverbanks, and taiga regions with sandy or muddy shorelines.
• Wintering Habitat:
  • Mangrove estuaries, tidal flats, salt pans, and sandy coastlines in warm tropical and subtropical regions.

Feeding & Foraging Behavior

• Diet:
  • Primarily insects, crustaceans, mollusks, and small aquatic invertebrates.
  • Occasionally consumes small fish and plant material.
• Foraging Technique:
  • Actively searches for prey by running along water edges, using its slender, upturned bill to probe into mud and sand.
  • Often seen in flocks with other shorebirds, darting quickly in a zig-zag motion.

Reproduction & Breeding Behavior

• Breeding Season: May to July.
• Nesting Sites:
  • Shallow scrapes on sandy or grassy riverbanks, typically near freshwater sources.
• Eggs & Incubation:
  • Lays 3–4 eggs, incubated for around 22–24 days.
  • Both parents share nesting and chick-rearing duties.
• Chick Development:
  • Hatchlings are precocial, meaning they can walk and forage within hours after hatching.

Special Features & Adaptations

• Upturned Beak:
  • Unusual among sandpipers, allowing it to efficiently probe mud and sand while foraging.
• Migratory Behavior:
  • Undertakes long-distance migrations between breeding and wintering grounds, sometimes covering over 10,000 km.
• Adaptability:
  • Thrives in both freshwater and saltwater environments, from inland rivers to coastal mudflats.

Presence of Terek Sandpiper in Sundarban

Occurrence in the Sundarban Biosphere

The Sundarban, the world’s largest mangrove ecosystem, serves as an important wintering and stopover site for the Terek Sandpiper. The region provides:

• Shallow tidal flats and mudflats, ideal for foraging.
• Brackish water environments supporting abundant crustaceans and mollusks.
• Undisturbed mangrove creeks, offering safe resting sites during high tide.

Seasonal Presence in Sundarban

• The Terek Sandpiper is a regular winter visitor to Sundarban, arriving between September and April.
• Peak sightings occur between November and February, when food availability is high in estuaries and mudflats.
• Occasionally, individuals are spotted in monsoon months, possibly due to changes in migration patterns or weather disturbances.

Ecological Importance in Sundarban

• Bioindicator of Wetland Health:
  • The presence of Terek Sandpipers signals healthy mudflats and estuaries, rich in benthic organisms.
• Role in the Food Chain:
  • Acts as a natural pest controller, feeding on aquatic insects.
  • Forms part of the prey base for larger raptors and predatory fish.

Threats & Conservation in Sundarban

Despite its Least Concern (LC) status on the IUCN Red List, the Terek Sandpiper faces multiple threats in the Sundarban region:

1. Habitat Loss:
   • Coastal development, land reclamation, and mangrove degradation impact wintering sites.
2. Pollution:
   • Industrial and agricultural runoff leads to water contamination, affecting prey availability.
3. Climate Change:
   • Rising sea levels and increased salinity could alter mudflat ecosystems, reducing foraging areas.
4. Disturbance from Human Activities:
   • Fishing, boating, and tourism in sensitive wetland areas may disrupt feeding and resting behavior.

Conservation Measures in Sundarban

• Strengthening Protected Areas:
  • Many parts of Sundarban fall under Ramsar Sites & UNESCO World Heritage Status, offering some legal protection.
• Wetland Conservation Initiatives:
  • Monitoring shorebird populations and maintaining tidal mudflats.
• Community Awareness Programs:
  • Educating local fishing communities to reduce disturbances near key bird habitats.

Conclusion

The Terek Sandpiper (Xenus cinereus) is a fascinating migratory shorebird that plays a crucial role in wetland ecosystems, including the Sundarban Biosphere Reserve. Its presence in the Sundarban signifies a thriving coastal wetland habitat, rich in biodiversity. However, conservation efforts are necessary to mitigate habitat loss, pollution, and climate change impacts, ensuring the long-term survival of this species in India’s most ecologically significant mangrove ecosystem.