Isolated from the rest of the world by water, island habitats evolve in ways that are different from the mainland and make for fascinating case studies. They are like nature’s terrariums: living, thriving, and constantly evolving microcosms of the planet that many biologists believe offer a deeper understanding of our planet’s biodiversity. Case in point, Charles Darwin, whose trip to the Galapagos Islands of Ecuador famously inspired the theory of evolution.
“However, these same characteristics also make islands fragile and vulnerable ecosystems,” points out the IUCN. When a plant or animal is restricted to a small area, a single epidemic could wipe out the entire species. This is one of the reasons that “islands have the highest proportion of recorded species extinctions. Eighty per cent of known species extinctions have occurred on islands, and 45 per cent of IUCN’s Red List endangered species occur on islands.” Habitat loss is often higher in island habitats, due to the heightened tug-of-war on resources between humans and other species.
This is what sets Narcondam apart. The tiny island in the Andaman archipelago, was entirely uninhabited by humans until 1968, when the government set up a police check-post there, for defence purposes. Today, Narcondam has a human population of 20 police personnel that live in a small camp near the beach. Tourists are not allowed to visit, and research initiatives too have been few and far between.
One of the reasons that Narcondam is off-limits is its location. “This remote island sanctuary forms a stepping stone in the long chain of submerged and semi-submerged hills which extend from Burma and includes the Andaman and Nicobar islands,” explains AB Chaudhuri in his book, Biodiversity of Mangroves. Another reason is to protect the rare Narcondam hornbill: a striking bird species that is found exclusively on this 6.8-sq-km piece of land. There are about 50-249 mature individuals on the island, according to the IUCN, but the handsome birds aren’t the only noteworthy species there.
The waters around Narcondam Island are rich in marine life. The island’s coral reef is inhabited by fan and whip coral, barrel sponges, and sea stars, according to a study conducted by TR Shankar Raman et al. The paper also mentions schools of bluefin tuna, damsel fish, butterfly fish, angel fish, sea cucumbers, and the infamous crown of thorns starfish: one of the largest species of sea stars on the planet, named for the venomous spines all over its body. Adults measure 18-30 cm and can have as many as 20 arms.
Narcondam has a dormant volcano, the peak of which is thickly forested with wet evergreen vegetation. Closer to the shore, the beach is covered with Ipomea plants, and coconut and banana trees, planted for the resident police. Geckos and monitor lizards can be seen in and around the accommodations, perched on large boulders or tree trunks.
Farther in from the beach, the vegetation gets denser. The canopy is higher and layered, and the forest floor is littered with leaves and riddled with muscular roots. Even though visibility is restricted by the vegetation, there is plenty to see, from birds and reptiles, to insects such as spiders and butterflies.
Interestingly, there is no record of any amphibians on Narcondam Island. “This is not unusual with remote volcanic islands,” explains Dr Shirish Manchi, an ornithologist from the Salim Ali Centre for Ornithology and Natural History, who studied the hornbills of Narcondam. Reptiles, however, are plentiful, like this brightly coloured emerald gecko.
Tytler’s skink, also known as Tytler’s mabuya (Eutropis tytleri) is a reptile endemic to the Andaman Islands. The small, beige lizards can be seen among leaf litter; they spend their days foraging, fighting, and hunting on the forest floor. Research papers on Narcondam Island also mention the presence of snakes, including the yellow-lipped sea krait and the paradise flying snake, which glides from treetops in the canopy.
The forest floor is teeming with activity. Amidst gently decomposing leaves, are forest crabs, armies of ants and termites. These invertebrates might be small in size, but they are crucial to the functioning of the forest habitat and perform the role of waste decomposers. There are 125 species of ants on the Andaman and Nicobar Islands, including seven endemic species; the diversity of ants on Narcondam is yet to be studied.
The signature spider (Argiope anasuja) is also found near the ground. Named for its zigzag style of weaving (visible on bottom left), these spiders craft expansive webs to trap insects. They are one of several species of arachnids found on Narcondam Island.
The only terrestrial mammals on Narcondam, apart from humans and rats are island flying foxes (Pteropus hypomelanus). These members of the bat family are key pollinators, and are found in island habitats across the Indo-Pacific region. They feed on a variety of fruits, flowers, and nectars, and allegedly consume half their body weight in food every day.
Mornings on Narcondam are marked by the sweet call of the common hill myna (Gracula religiosa). These birds have a large range, both geographically and vocally. They are found in hilly habitats across Southeast and South Asia, and are known for their vocal range that includes melodies, whistles, and shrill, bursting calls. For this reason, the common hill myna has become popular in pet markets around the world; some believe they can be trained to speak human phrases.
The white-breasted waterhen (Amaurornis phoenicurus) is another common resident of Narcondam Island. According to the website eBird, this “medium-sized, chicken-like marsh bird is found in meadows, ditches, riversides, marshes, as well as parks and farmlands in close proximity to humans”. On Narcondam they can be seen walking along the shore and around the police camp, looking for food. Their diet includes insects, worms, and some plants.
Narcondam has a healthy population of the pied imperial pigeon (Ducula bicolor). These tuxedoed birds — “pied” is a term used for bird species that have two or more colours — inhabit rocky cliffs on the island, and survive on a diet of fruits such as figs and berries. “They are among the most powerful and agile flyers in the bird world,” says bird conservation website, Aviary. “This has enabled them to colonise many different islands across expansive stretches of open water.”
Daurian starlings or purple-backed starlings (Agropsar sturninus) are a rare sighting in most of India. However, they were frequently seen during photographer Dhritiman Mukherjee’s visit to Narcondam. At other times, flocks of around 100 Daurian starlings have been spotted on Narcondam, but like many things on this little island in the Indian Ocean, they are an enigma.
