The Andaman Islands are an archipelago located in the Bay of Bengal, part of the Indian Union Territory of the Andaman and Nicobar Islands. The islands are home to a rich diversity of flora and fauna, including a number of endemic bird species found nowhere else on Earth.
The Andaman Islands were formed through volcanic activity and are covered in lush tropical rainforests. Their isolation and diversity of habitats have allowed unique species to evolve here. At least 10 resident bird species are endemic to the Andaman Islands, found only on these islands and nowhere else globally.
Understanding which birds are endemic to the Andaman Islands requires analyzing the islands’ geography, ecology, and species. This article will provide an overview of the Andaman Islands, their forests and habitats, the key endemic bird species, and why these birds are limited to these islands.
Overview of the Andaman Islands
The Andaman Islands are an archipelago of over 300 islands, islets and rocks located in the southeastern Bay of Bengal. The Andaman Sea separates the islands from Myanmar to the north and the Nicobar Islands to the south.
The main islands of the Andaman archipelago are North Andaman, Middle Andaman, South Andaman and Little Andaman. The islands encompass a total land area of approximately 6,408 square km.
The islands have a tropical monsoon climate, with average temperatures of 28–32°C and heavy rainfall of 3,000–5,000 mm annually.
The Andaman Islands have a complex geological history. They were once connected to the Indian subcontinent, but separated approximately 10 million years ago due to tectonic activity. The islands feature rugged relief with dense tropical rainforests, mangrove swamps and coral reefs.
This isolated tropical environment has given rise to high levels of biodiversity and endemism, including birds found nowhere else on Earth. The Andaman Islands host over 300 species of birds, of which 10 are endemic residents.
Forests and Habitats of the Andaman Islands
The Andaman Islands host a variety of habitat types that support diverse and endemic wildlife. The main habitat types include:
– Tropical wet evergreen forests – The most widespread habitat, supporting broadleaf trees, palms, woody climbers, orchids, ferns and more. Found up to elevations of 600 m.
– Mangrove forests – Located along tidal rivers and coastlines, dominated by species like mangrove apple, mangrove palm and giant leather fern. Provide key habitat for several endemic birds.
– Coral reefs – Fringing and patch reefs with high coral cover surround many of the Andaman Islands, supporting reef fish, turtles, and shorebirds.
– Mudflats and sandy beaches – Found between mangrove forests and coral reefs. Used by migratory and resident shorebirds.
– Freshwater swamps – Scattered along the wet evergreen forest floors. Dominated by pandanus trees, saw-grass and cane brakes.
– Secondary forests – Found where original forest cover has been logged or cleared for plantations. Still provide habitat for some endemic birds.
This mosaic of habitats provides niche environments that have given rise to specialized endemic bird species like the Andaman crake and Andaman coucal. Protecting this habitat diversity is key for conservation.
Endemic Birds of the Andaman Islands
At least 10 resident bird species are considered endemic to the Andaman Islands. They are found only on these islands and have evolved in isolation here. The key endemic birds of the Andaman Islands include:
Andaman Crake
– Scientific Name: Rallina canningi
– IUCN Status: Endangered
– Habitat: Dense forest undergrowth and swampy areas
– Description: A small, secretive forest rail with a rufous collar and barred underparts. Rather indistinct vocalizations.
Andaman Cuckoo-Dove
– Scientific Name: Macropygia rufipennis andamanica
– IUCN Status: Vulnerable
– Habitat: Broadleaf evergreen forest canopy
– Description: A subspecies of the rufous-winged cuckoo dove. Bright cinnamon plumage with a grey head.
Andaman Coucal
– Scientific Name: Centropus andamanensis
– IUCN Status: Critically Endangered
– Habitat: Middle story of broadleaf forests
– Description: A large black coucal with a green gloss and blue eye-ring. Loud “woop-woop” call.
Andaman Woodpecker
– Scientific Name: Sapheopipo noguchii
– IUCN Status: Vulnerable
– Habitat: Broadleaf forest canopy
– Description: A large black woodpecker with a red cap. Sharp rattling call.
Andaman Drongo
– Scientific Name: Dicrurus andamanensis
– IUCN Status: Least Concern
– Habitat: Broadleaf forest canopy and clearings
– Description: Black and glossy with a forked tail. Metallic calls.
Andaman Treepie
– Scientific Name: Dendrocitta bayleyii
– IUCN Status: Endangered
– Habitat: Broadleaf canopy and mangroves
– Description: Conspicuous black and white crow with a long graduated tail.
Andaman Bulbul
– Scientific Name: Hypsipetes virescens
– IUCN Status: Near Threatened
– Habitat: Broadleaf and mangrove forests
– Description: Olive bulbul with yellow vent and undertail. Musical whistles.
Andaman Scops Owl
– Scientific Name: Otus balli
– IUCN Status: Least Concern
– Habitat: Dense broadleaf forest canopy
– Description: A small rufous and brown owl. Four-note whistling calls.
Andaman Hawk-Owl
– Scientific Name: Ninox affinis andamanensis
– IUCN Status: Vulnerable
– Habitat: Dense broadleaf forest understory
– Description: A dark brown hawk-owl with heavily barred underparts.
Andaman Masked Owl
– Scientific Name: Tyto deroepstorffi
– IUCN Status: Vulnerable
– Habitat: Dense broadleaf forest understory near streams
– Description: A reddish-brown masked owl with no ear tufts.
Geographic Isolation and Evolution
The Andaman Islands have been isolated for millions of years since separating from the Indian mainland. This allowed the endemic birds to evolve in situ without competition from continental species. They adapted to specialized niches and habitats on the islands.
For example, the Andaman crake likely descended from other forest rail species. In isolation on the Andaman Islands, it evolved distinct plumage and vocalizations adapted to dense rainforest understories.
The Andaman Islands also lacked large predators, allowing vulnerable endemic birds like the Andaman coucal to thrive in evolutionary niches they would not inhabit on the mainland.
Over time, the Andaman birds diverged significantly from their ancestral mainland populations. They are now genetically, morphologically and behaviorally distinct – a unique natural heritage of these islands.
Threats and Conservation
Many of the Andaman Islands’ endemic birds are threatened by habitat loss, invasive species and overhunting:
– Habitat loss – Logging, plantations and development have destroyed native rainforest cover. 75% of forest has already been lost.
– Invasive species – Cats, rats and mynas outcompete and prey on endemic birds.
– Overhunting – Several endemics are hunted for food, traditional medicine or feathers.
As a result, all the endemic birds except the Andaman drongo are considered threatened on the IUCN Red List. Urgent action is needed to prevent extinctions.
Key conservation actions include:
– Expanding protected areas and stopping deforestation of native habitat.
– Eradicating invasive predators from protected forests.
– Banning hunting and trade of endemic birds.
– Restoring degraded forests with native species.
– Raising awareness of endemics to foster pride and support for conservation.
With prompt efforts, the unique avifauna of the Andamans can persist well into the future.
Conclusion
The Andaman Islands host at least 10 endemic resident bird species that evolved in isolation on these islands. Due to the Andamans’ remoteness and habitat diversity, specialized birds like the Andaman coucal and Andaman crake arose here. However, habitat loss and hunting now threaten the survival of these unique birds. Protecting the Andamans’ endemic avifauna through expanded conservation efforts is crucial. With the extinction crisis escalating globally, safeguarding the endemic biodiversity of islands like these is more important than ever.
