Red‐necked Stint (Calidris ruficollis) – A Comprehensive Overview
Taxonomy and Classification
- Kingdom: Animalia
- Phylum: Chordata
- Class: Aves
- Order: Charadriiformes
- Family: Scolopacidae
- Genus: Calidris
- Species: Calidris ruficollis
The Red‐necked Stint (Calidris ruficollis) belongs to the family Scolopacidae, which includes sandpipers and allies. It is a small migratory shorebird known for its distinct reddish neck during the breeding season.
Morphology and Physical Characteristics
- Size: Approximately 13–16 cm in length.
- Wingspan: Ranges between 28–37 cm.
- Weight: Weighs around 20–30 grams.
- Plumage:
- Breeding Season: Exhibits a reddish-orange throat and upper breast, giving it the name Red-necked Stint. The upper parts are brownish with streaks, while the underparts are white.
- Non-breeding Season: Loses its vibrant color, turning into a more uniform pale grey above and white below.
- Bill and Legs: Black and relatively short, well-adapted for foraging in soft mud and sand.
- Eyes: Dark and round, providing keen vision for detecting small invertebrates.
Habitat and Distribution
- Primary Breeding Grounds:
- The tundra regions of Siberia and northern Russia.
- Migration and Wintering Grounds:
- Undertakes a long-distance migration to Australia, Southeast Asia, and South Asia, including India and the Sundarban region.
- Preferred Habitats:
- Coastal mudflats, intertidal zones, estuaries, sandy beaches, and wetlands.
- Frequently observed in mangrove swamps, lagoons, and brackish water bodies, especially in wintering sites.
Diet and Feeding Behavior
- Primary Diet:
- Small crustaceans, mollusks, insects, and marine worms found in mudflats.
- Foraging Technique:
- Uses a probing technique, inserting its short bill into wet sand and mud to extract prey.
- Actively feeds during low tide, covering large areas in search of food.
Breeding and Reproduction
- Breeding Season: May to July.
- Nesting:
- Nests in the Arctic tundra, where it lays eggs in small depressions on the ground, lined with moss and lichens.
- Clutch Size: Typically 3–4 eggs.
- Parental Care:
- Both parents participate in incubation, but the female often departs early, leaving the male to care for the chicks.
- Chick Development:
- Hatchlings are precocial (able to move and feed shortly after hatching).
Special Features and Adaptations
- Long-Distance Migratory Ability:
- Capable of traveling over 10,000 km between breeding and wintering grounds.
- Seasonal Plumage Change:
- Reddish throat in breeding season helps in mate attraction, while duller colors in winter provide camouflage.
- Efficient Foraging Strategy:
- Uses rapid pecking movements and probing behavior to find food in soft sediments.
- Strong Flight Capability:
- Highly adapted for long non-stop flights over oceans and continents.
Presence of Red‐necked Stint in the Sundarban
The Sundarban, the world’s largest mangrove ecosystem, is an important stopover and wintering ground for migratory shorebirds, including the Red‐necked Stint. This bird is commonly spotted in:
- Intertidal mudflats and sandbanks along river estuaries.
- Brackish water wetlands with rich invertebrate life.
- Mangrove fringes, where small crustaceans and insects thrive.
Ecological Significance in Sundarban
- Indicator Species:
- The presence of Red‐necked Stint in Sundarban signifies a healthy coastal and wetland ecosystem.
- Role in the Food Chain:
- Contributes to controlling small invertebrate populations.
- Serves as prey for larger predatory birds like peregrine falcons.
- Migration Stopover:
- Acts as a crucial resting and feeding site before the birds continue their journey further south.
Conservation Status and Threats
- IUCN Red List: Least Concern (LC) but faces habitat threats.
- Major Threats:
- Coastal habitat destruction (due to human encroachment and industrialization).
- Climate change affecting migratory patterns.
- Pollution and plastic waste in feeding grounds.
Conservation Efforts in Sundarban
- Protected Wetlands: Conservation of Sundarban Biosphere Reserve helps maintain migratory bird habitats.
- Eco-tourism Awareness: Sustainable tourism initiatives educate visitors on preserving fragile ecosystems.
- Mangrove Conservation: Essential for maintaining brackish water ecosystems where these birds thrive.
Conclusion
The Red‐necked Stint (Calidris ruficollis) is a remarkable migratory shorebird that plays an essential role in the Sundarban ecosystem. Its presence highlights the region’s importance as a critical wintering and stopover site. However, conservation measures are necessary to protect its habitat from anthropogenic pressures. Preserving the Sundarban’s wetlands and intertidal zones will ensure that this small yet vital shorebird continues its incredible migration cycle for generations to come.