Wildlife of
Andaman and Nicobar Islands

Primary Threats

• Warmer seas cause coral bleaching and weaker reefs. Sea-level rise and storms eat away low nesting beaches (especially Nicobar and Little Andaman) and flood wetlands. Stronger cyclones and changing rain cause tree falls and landslides, harming local forest animals, mangroves, seagrass, and dugong.
• Coastal and lowland forest habitats are lost or fragmented by settlement expansion, tourism facilities, and associated utilities, especially around South Andaman; shoreline erosion and land subsidence/uplift after the 2004 tsunami also permanently altered coastal habitats, reducing suitable nesting and foraging areas in some islands.
• Road widening, new links, ports/harbors, jetties, and airport/defense-related development increase fragmentation and edge effects in forests and mangroves; dredging and reclamation elevate turbidity and smother nearshore reefs and seagrass, directly affecting fish nurseries and dugong feeding grounds.
• High dependence on reef-associated fisheries and nearshore resources leads to localized depletion of reef fish and invertebrates; opportunistic targeting of high-value species (e.g., groupers, sea cucumbers) and bycatch risks for turtles increase with fishing effort and expanding market access.
• Illegal or opportunistic trade/collection can include turtle products and curio shells, and exploitation of other protected wildlife; the remoteness of outer islands complicates enforcement and increases the likelihood that illegal take goes undetected.
• Localized hunting and egg collection (including megapode eggs in parts of the Nicobars) can depress small island populations; hunting pressure may rise after extreme weather events when supply chains are disrupted and communities rely more on local protein sources.
• Tourism and recreational use of beaches and lagoons (night lighting, vehicles, crowding) disturb nesting turtles and shorebirds; boat traffic, anchoring, and snorkeling/diving activity can physically damage coral and seagrass and increase stress on sensitive sites inside and adjacent to marine protected areas.
• Marine plastic debris accumulates on remote beaches and reefs; untreated/partially treated sewage and coastal runoff near towns increase nutrient loads, promoting algal growth on reefs; oil/chemical spill risk is elevated by major shipping routes through the Bay of Bengal and local harbor operations.
• Introduced rats, cats, dogs, and invasive weeds impact island-nesting birds and reptiles through predation and habitat alteration; invasive predators are especially damaging on small islets where endemic species have limited refugia.
• Many endemics occur in very small, isolated populations restricted to single islands (e.g., Narcondam hornbill on Narcondam), making them vulnerable to inbreeding, demographic stochasticity, and rapid declines after cyclones, disease outbreaks, or habitat shocks.
• Coral disease and stress-related mortality can rise following heatwaves and sedimentation; on land, spillover risks from domestic animals (dogs/poultry) can affect native fauna in and near villages, particularly where free-ranging animals overlap with forest edges.
• Saltwater crocodile encounters near creeks and estuaries can lead to conflict and retaliatory actions; interactions with free-ranging domestic animals and commensal wildlife near settlements can increase conflict risks and complicate coexistence around protected-area boundaries.
• Shoreline armoring, dredging, and reclamation alter currents and sediment regimes, degrading mangroves, reefs, and seagrass; changes to freshwater flows from small catchments (e.g., water extraction and altered drainage) can affect estuarine salinity and mangrove health.
• While large-scale commercial extraction has been curtailed relative to the past, legacy impacts remain (access roads, altered forest structure), and illegal/unsanctioned cutting can persist locally; plantation forestry can simplify habitat compared to native multi-layer rainforest.
• Rapid growth around Port Blair and other hubs increases land conversion, demand for sand/stone/wood, solid waste, wastewater loads, and traffic-amplifying pressure on adjacent forests, mangroves, and nearshore reefs.
• Expansion/intensification of crops (e.g., coconut/arecanut and mixed smallholder plots) can replace native forest on flatter lowlands and increase pesticide/fertilizer runoff into creeks, lagoons, and reef areas.
• Extraction of freshwater from small island aquifers, sand removal for construction, and heavy nearshore harvesting reduce ecosystem resilience; seagrass meadows used by dugong are vulnerable to cumulative impacts from harvesting pressure, siltation, and anchoring.
• Large-scale mining is limited, but localized quarrying for construction materials can cause habitat loss, sediment runoff, and slope instability, with downstream impacts on streams, mangroves, and nearshore coral communities.