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Nicobar Pigeon (Nicobar Dove)
The Nicobar pigeon, scientifically known as Caloenas nicobarica, is an exquisite bird inhabiting small islands and coastal regions stretching from the Andaman and Nicobar Islands in India, across the Indonesian Archipelago, to the Solomons and Palau. Remarkably, it stands as the sole surviving member of the Caloenas genus, with its extinct relatives including the spotted green pigeon and Kanaka pigeon. Furthermore, it holds a significant evolutionary connection as the closest living relative to the extinct dodo and Rodrigues solitaire.
Renowned for its stunning appearance, the Nicobar Pigeon graces its habitat with a dark slaty grey body adorned with lustrous metallic blue-green and copper-bronze upperparts. Its distinguishing features include mane-like neck hackles that shimmer and sharply contrasting white tail coverts and tail. Notably, females exhibit smaller sizes with shorter neck hackles and brown underparts, while the young are born with dull grey plumage, lacking the characteristic neck hackles, and a bronzy green tail.
Despite its majestic presence, the Nicobar Pigeon faces numerous challenges, contributing to its declining population status. Once abundant across its range, the species now grapples with threats such as capture for the pet trade and consumption as food. Moreover, habitat loss, exacerbated by deforestation for plantations, poses a significant risk to its survival. The invasion of alien predators like rats and cats further compounds the species’ struggle for survival.
In its natural habitat, the Nicobar Pigeon exhibits both solitary behavior and congregates in flocks, typically ranging from 20 to 30 individuals. While it boasts swift and powerful flight capabilities, it predominantly forages on the forest floor, feasting on fleshy fruits and seeds. During the breeding season from January to March, females construct nests using twigs, perched high on evergreen trees to safeguard their eggs.
Regrettably, the Nicobar Pigeon’s conservation status paints a concerning picture, categorized as Near Threatened on the IUCN Red List and listed in Appendix 1 of CITES. Urgent conservation efforts are imperative to safeguard this avian jewel from further decline. Efforts to combat illegal capture, address habitat destruction, and mitigate the impact of invasive species are crucial steps in securing the future of the Nicobar Pigeon and preserving its ecological significance for generations to come.
Scientific Classification
| Domain | Eukaryota |
| Kingdom | Animalia |
| Phylum | Chordata |
| Class | Aves |
| Order | Columbiformes |
| Family | Columbidae |
| Genus | Caloenas |
| Species | C. nicobarica |
Taxonomy
In 1738, the Nicobar pigeon made its debut in the scientific realm when English naturalist Eleazar Albin included a detailed description and two illustrations of the species in his seminal work, A Natural History of Birds. Fast forward to 1758, and the Swedish naturalist Carl Linnaeus, in the tenth edition of his Systema Naturae, categorized the Nicobar pigeon within the genus Columba, alongside other pigeon species. Linnaeus christened the bird with the binomial name Columba nicobarica, citing Albin’s invaluable contributions. However, it wasn’t until 1840 that English zoologist George Robert Gray bestowed upon the Nicobar pigeon the honor of being the type species for the newly erected genus Caloenas.
Binomial name
Caloenas nicobarica (Linnaeus, 1758)
Synonyms
Columba nicobarica Linnaeus, 1758
Taxonomically, the Nicobar pigeon boasts two recognized subspecies: C. n. nicobarica, spanning from the Andaman and Nicobar Islands to New Guinea and the Solomon Islands, and C. n. pelewensis, exclusively inhabiting Palau Island. Intriguingly, cladistic analyses of mitochondrial DNA sequences have proposed the Nicobar pigeon as a probable closest living relative of the extinct didines, including the renowned dodo. Nevertheless, such conclusions remain tentative, underscored by the need for comprehensive genetic studies encompassing a broader taxonomic spectrum within the Columbidae family.
Evolutionary analyses place the Nicobar pigeon amidst a diverse Indopacific radiation, alongside distinctive columbiform species like the tooth-billed pigeon and the crowned pigeons. While uncertainties persist regarding its precise phylogenetic placement, the Nicobar pigeon’s singular attributes and ancient lineage underscore its significance as a living relic from the Paleogene era, dating back some 56-34 million years ago.
Tragically, the Nicobar pigeon shares a fate with its extinct relatives, such as the Kanaka pigeon and the Spotted green pigeon. The former, larger than its surviving counterpart, likely fell prey to human exploitation and vanished from its native habitats by 500 BC. Similarly, the Spotted green pigeon, a more recent casualty of the 19th century, succumbed to the invasive presence of European rats. These extinctions serve as poignant reminders of the delicate balance between human activities and the preservation of biodiversity within fragile island ecosystems.
Description
The Nicobar pigeon presents itself as a majestic avian specimen, boasting a sizable frame measuring 40 cm (16 in) in length. Its distinguished features include a head adorned in elegant grey plumage, seamlessly transitioning into resplendent green and copper hackles along the upper neck. Notably, its tail, albeit short, exudes purity in its pristine white hue, providing a striking contrast to the metallic green sheen that envelops the remainder of its plumage. A distinguishing characteristic lies in the dark bill’s cere, forming a subtle blackish knob, while its sturdy legs and feet sport a subdued red hue. Piercing irises gaze from its visage, adding depth to its captivating presence.
Intriguingly, sexual dimorphism subtly manifests in this avian species, with females exhibiting slight diminishment in size compared to their male counterparts. Their features include a smaller bill knob, abbreviated hackles, and a warmer tone in the underparts. Juvenile Nicobar pigeons, characterized by a black tail and a lack of iridescence, undergo a gradual transformation as they mature into their resplendent adult plumage. Remarkably, minimal variations punctuate the species across its expansive range, with even the Palau subspecies, C. n. pelewensis, showcasing near-identical traits save for shorter neck hackles.
The vocal prowess of the Nicobar pigeon adds another layer of intrigue to its allure, as it emits a distinctive low-pitched repetitive call, echoing through its habitat with an air of authority and grace. This auditory signature serves not only as a means of communication but also as a testament to the species’ rich behavioral repertoire and social dynamics within its community.
| Aspect | Description |
|---|---|
| Size | Large, measuring approximately 40 cm (16 in) in length |
| Plumage | Head and upper neck plumage are grey, transitioning into green and copper hackles; metallic green plumage with a short, pure white tail |
| Sexual Dimorphism | Females are slightly smaller with a smaller bill knob, shorter hackles, and browner underparts |
| Variation | Minimal variation across the species’ wide range, including the Palau subspecies, which is nearly identical with shorter neck hackles |
| Vocalization | Very vocal species, emitting a low-pitched repetitive call |
