North Sentinel Island, a remote land in the Bay of Bengal, is home to the uncontacted Sentinelese people and a largely untouched natural environment. Its profound isolation contributes to the mystery surrounding its biodiversity, with much of its wildlife remaining unobserved by the outside world.
Island Habitat and Ecosystem
North Sentinel Island, covering approximately 60 square kilometers, features a dense tropical rainforest that blankets most of its interior. Along its coastline, mangrove forests provide a transitional habitat between land and sea. The island is encircled by extensive coral reefs, which act as natural barriers. This tropical environment experiences heavy rainfall, high humidity, and consistently warm temperatures, influenced by seasonal monsoons.
These geographical and climatic elements foster a diverse, albeit challenging, habitat for various life forms. The 2004 Indian Ocean earthquake uplifted previously submerged coral reefs and altered coastal areas. Despite these changes, its isolation has preserved a distinct ecosystem, largely free from external human interference.
Terrestrial Wildlife
The island is known to host Indian wild boar, which are a food source for the Sentinelese people. Another notable inhabitant is the coconut crab, a large terrestrial crustacean that thrives on the island, having been largely extirpated from other Andaman Islands.
North Sentinel Island is recognized as a globally Important Bird Area, suggesting a rich diversity of birdlife, despite the lack of comprehensive surveys. Bird species likely present include the Pied imperial pigeon, Nicobar pigeon, and the Andaman crake, based on their presence in the broader Andaman archipelago. Reptiles such as various snakes, lizards, and monitor lizards are probable inhabitants, along with saltwater crocodiles in coastal areas. Small mammals like rodents and bats are also expected to be part of the island’s fauna.
Marine Life in Surrounding Waters
The waters surrounding North Sentinel Island support a rich marine ecosystem, particularly within its extensive coral reefs. These reefs provide habitat for diverse fish species, crustaceans, and mollusks. Sea turtles, including green and leatherback turtles, inhabit the area and are a food source for the island’s inhabitants.
Marine mammals common to the Andaman Sea, such as dolphins and dugongs, have been recorded near the island. While some reef bleaching occurred due to the 1998 El Niño, coral regeneration has been observed, indicating the resilience of this marine environment. Sharks have also been reported in the surrounding waters.
Challenges in Wildlife Study
Direct observation of North Sentinel Island’s terrestrial animals is limited, with much information inferred from aerial surveys, historical accounts, and studies of nearby Andaman Islands. Comprehensive study of the island’s wildlife faces considerable challenges. The Indian government strictly protects the island, prohibiting unauthorized access to safeguard the uncontacted Sentinelese from external diseases. This protective stance means direct scientific expeditions and on-site wildlife surveys are not permitted.
Information regarding the island’s animal populations is primarily derived from distant observations, limited aerial reconnaissance, or inferences from the wider Andaman and Nicobar archipelago. The Sentinelese people’s consistent hostility towards outsiders further deters close approach, making detailed biological research impractical and dangerous. Consequently, the exact composition and dynamics of North Sentinel Island’s animal life remain largely uncataloged.