Common Redshank (Tringa totanus) – A Detailed Overview
The Common Redshank (Tringa totanus) is a medium-sized wader bird known for its striking red legs and distinctive call. It belongs to the sandpiper family and is widely found in wetlands, estuaries, and coastal regions, including the Sundarban. This detailed account covers the bird’s taxonomy, morphology, habitat, behavior, and its presence in the Sundarban ecosystem.
Taxonomy and Classification
- Kingdom: Animalia
- Phylum: Chordata
- Class: Aves
- Order: Charadriiformes
- Family: Scolopacidae
- Genus: Tringa
- Species: Tringa totanus
The Common Redshank is closely related to other shorebirds in the Tringa genus, such as the Lesser Yellowlegs (Tringa flavipes) and Spotted Redshank (Tringa erythropus).
Morphology and Identification
The Common Redshank is a medium-sized wading bird with a body length of approximately 27–29 cm, a wingspan of 62–69 cm, and an average weight of 90–150 g.
Key Identification Features:
- Legs: Bright red or orange-red legs, which are its most distinguishing feature.
- Bill: Medium-length, straight, with a red base and black tip.
- Plumage:
- Breeding Season: Brownish-grey upperparts with dark streaks and a paler, finely speckled underside.
- Non-Breeding Season: More uniform greyish-brown, with a less distinct pattern.
- Wings: White wing bars visible in flight.
- Call: A loud, repetitive “tew-tew-tew” alarm call, making it one of the noisiest waders in its habitat.
Habitat and Distribution
The Common Redshank is widely distributed across Europe, Asia, and North Africa. It prefers:
- Coastal areas, mudflats, salt marshes, and mangroves.
- Freshwater wetlands, including lakeshores and riverbanks.
- Grasslands and meadows, especially during migration and wintering periods.
Migration
This species is a partial migrant. Northern populations from Scandinavia, Russia, and Central Asia migrate to warmer regions in Africa, the Middle East, and South Asia, including India and the Sundarban.
Diet and Feeding Behavior
The Common Redshank is an opportunistic feeder, primarily feeding on:
- Invertebrates such as worms, mollusks, crustaceans, and small aquatic insects.
- Small fish and amphibians (occasionally).
- Plant material such as seeds and algae (in scarce food conditions).
It uses its long, sensitive bill to probe into mudflats and shallow waters in search of food, often foraging alone or in small groups.
Breeding and Nesting
- Breeding Season: April to July.
- Nesting Sites: Grasslands, coastal marshes, and wet meadows.
- Nest Type: A simple scrape in the ground, lined with grass and leaves.
- Eggs: Typically 3–5 eggs, pale brown with dark speckles.
- Incubation Period: 22–25 days, both parents share incubation duties.
- Chick Development: Precocial (can walk and feed shortly after hatching). Chicks fledge in 30–35 days.
Special Features and Adaptations
- Bright red legs serve as a warning signal to other waders when a predator is near.
- Excellent camouflage due to their cryptic brown and grey plumage, which helps protect them from predators.
- Highly vocal, often alerting other birds in the area with their loud calls.
- Strong fliers, capable of rapid long-distance migration.
Common Redshank in the Sundarban
The Sundarban, a vast and biodiverse mangrove ecosystem, serves as an important wintering ground for the Common Redshank. It thrives in the intertidal mudflats, estuarine creeks, and mangrove swamps of this region.
Why is the Sundarban Important for the Common Redshank?
- Rich Feeding Grounds:
- The Sundarban’s tidal mudflats provide an abundance of invertebrates, making it an ideal foraging site.
- Seasonal Migration Stopover:
- The bird uses Sundarban’s wetlands as a migratory stopover during its journey from breeding grounds in Eurasia.
- Protection from Predators:
- The dense mangrove vegetation offers excellent shelter against predation.
- Climate Buffer:
- The mild winter temperatures of the Sundarban provide a favorable habitat for overwintering.
Threats to the Common Redshank in Sundarban
Despite being a species of Least Concern (IUCN Red List), several factors pose threats to their population in the Sundarban:
- Habitat Destruction: Mangrove deforestation and coastal development impact their feeding and nesting sites.
- Climate Change: Rising sea levels and erratic weather patterns affect their habitat.
- Pollution: Oil spills, plastic waste, and industrial pollutants contaminate their wetland environment.
- Overfishing: Reduction in aquatic prey due to human activities disrupts their food supply.
Conservation and Protection
Global Measures
- Listed under the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA).
- Part of Ramsar wetland protection initiatives.
Sundarban-Specific Conservation
- Mangrove afforestation projects help in maintaining habitat integrity.
- Protected wetland areas in the Sundarban Biosphere Reserve support wintering populations.
- Community awareness programs encourage sustainable fishing and wetland preservation.
Conclusion
The Common Redshank (Tringa totanus) is an important indicator species of healthy wetland ecosystems. Its presence in the Sundarban highlights the ecological richness of this mangrove region. However, conservation efforts are crucial to maintaining its habitat and ensuring that the Sundarban remains a thriving wintering ground for this remarkable shorebird.
Protecting the Sundarban means protecting migratory birds like the Common Redshank and preserving the delicate balance of nature.