Nicobar Pigeon (Caloenas nicobarica)

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February 14, 2025
Flora & Fauna

Nicobar Pigeon (Caloenas nicobarica) – A Comprehensive Study

Taxonomy & Classification

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Aves
  • Order: Columbiformes
  • Family: Columbidae
  • Genus: Caloenas
  • Species: Caloenas nicobarica

The Nicobar Pigeon (Caloenas nicobarica) is one of the most visually striking members of the pigeon family Columbidae. It is considered the closest living relative of the extinct Dodo (Raphus cucullatus), making it a species of significant evolutionary interest.

Morphology & Physical Description

  • Size: 40 cm (16 inches) in length
  • Weight: 450–600 grams
  • Plumage:
    • Iridescent metallic feathers with hues of green, blue, bronze, and copper
    • The head and upper neck are greyish with elongated hackles (hair-like feathers)
    • Underparts and tail: The short, white tail contrasts sharply with the dark body
  • Eyes: Dark brown or black
  • Beak: Black with a distinct cere (fleshy protuberance) at the base
  • Legs & Feet: Reddish in color with strong claws adapted for perching
  • Wingspan: Moderate but strong, adapted for long-distance flights between islands

Habitat & Distribution

The Nicobar Pigeon is a terrestrial and arboreal bird primarily found in tropical and subtropical regions, including:

  • Coastal forests, mangroves, and small offshore islands
  • Dense lowland rainforests with minimal human disturbance
  • Rocky islets and atolls that provide safe nesting grounds

Geographical Range

It is native to:

  • The Nicobar Islands and Andaman Islands of India
  • Coastal regions of Southeast Asia (Thailand, Malaysia, Indonesia, Philippines)
  • Parts of Papua New Guinea and the Solomon Islands

Presence in the Sundarban

The Sundarban, the largest mangrove forest in the world, provides a suitable environment for many pigeon species. However, the Nicobar Pigeon is rarely recorded in the Sundarban region.

Factors Limiting Its Presence in the Sundarban:

  1. Habitat Preference: Prefers isolated islands with less human interference, unlike the Sundarban, which has a complex tidal ecosystem with fluctuating salinity.
  2. Predation Pressure: The dense tiger-dominated ecosystem poses higher risks from predators like hawks, eagles, and large reptiles.
  3. Food Availability: While the Sundarban provides fruits and seeds, it lacks the rocky coastal habitats that Nicobar Pigeons prefer for nesting.

Despite these factors, occasional sightings may occur along the eastern periphery of the Sundarban, especially near coastal forest patches with dense tree canopies.

Diet & Feeding Behavior

The Nicobar Pigeon is an omnivorous bird, with its diet consisting of:

  • Seeds and fruits (figs, berries, nuts)
  • Small invertebrates (insects, mollusks)
  • Sprouted grains and leaves
  • Occasionally consumes snails and land crustaceans, helping with calcium intake for eggshell formation

Foraging Strategy

  • Ground Feeder: Walks through forest floors, leaf litter, and mangroves to search for food
  • Gizzard Stones: Swallows small pebbles to help grind hard seeds
  • Social Feeding: Often feeds in flocks, enhancing protection against predators

Breeding & Nesting

  • Breeding Season: Varies based on region, but generally between March and August
  • Nest Type: A loosely-built platform of twigs placed on tree branches or rocky ledges
  • Eggs: Usually one egg per clutch, pale white or cream-colored
  • Incubation: Both parents share incubation duties for about 30 days
  • Chick Rearing:
    • Nestlings are fed with “pigeon milk”, a nutrient-rich secretion from the parents’ crop
    • Fledglings stay in the nest for about 40-45 days before becoming independent

Behavior & Social Structure

  • Highly Gregarious: Moves in flocks of 10-30 individuals
  • Long-Distance Traveler: Known to fly between islands in search of food and breeding sites
  • Shy & Elusive: Prefers dense forest cover and avoids human settlements

Special Features & Adaptations

  1. Iridescent Plumage: Acts as camouflage in dense forests, making it harder for predators to detect.
  2. Strong Wing Muscles: Adapted for long-distance migration between islands.
  3. White Tail Signal: Helps flock members stay visible in dimly-lit forest environments.
  4. Hard Gizzard Lining: Allows digestion of hard seeds and nuts that other birds may avoid.

Threats & Conservation Status

Major Threats

  • Habitat Destruction: Deforestation and coastal development are reducing nesting sites.
  • Poaching & Illegal Trade: Nicobar Pigeons are hunted for food, feathers, and the pet trade.
  • Predation by Invasive Species: Introduction of rats, cats, and monkeys on islands has led to egg predation.

Conservation Measures

  • Listed as Near Threatened (NT) by the IUCN due to population decline
  • Protected under CITES Appendix I, restricting international trade
  • Nicobar Islands declared a Biosphere Reserve to conserve natural populations
  • Ecotourism control measures to limit human impact on their nesting grounds

Conclusion

The Nicobar Pigeon (Caloenas nicobarica) is a unique, colorful pigeon species with an important ecological role in seed dispersal and island ecosystems. While its presence in the Sundarban is limited, its close relation to tropical mangrove forests and coastal regions makes it an important species in the broader Indian Ocean biodiversity. Strict conservation efforts are essential to protect this rare and magnificent bird from extinction.