Wildlife of
Indonesia

Primary Threats

• Conversion and fragmentation of lowland rainforests, peat swamp forests, and mangroves-especially in Sumatra, Kalimantan (Borneo), and parts of Papua-driven by plantations, smallholder expansion, settlements, and associated road networks. This reduces core habitat for orangutans and other endemics and isolates populations on islands and peninsulas.
• Expansion of oil palm and pulpwood plantations, plus smallholder agriculture, is a major land-use driver in Sumatra and Kalimantan; in some areas of Papua and Sulawesi it is emerging or growing. This often occurs via drainage of peatlands, clearing of secondary forests, and encroachment near protected areas, increasing human-wildlife encounters and fire risk.
• Legal and illegal logging in production forests and at forest frontiers reduces forest quality and canopy connectivity (critical for arboreal species like orangutans and gibbons). Selective logging and road access can catalyze subsequent clearing and settlement, particularly in Kalimantan and Papua.
• Nickel mining (notably in Sulawesi and Halmahera) and coal and gold mining in other regions drive forest loss, road building, erosion, and sediment runoff to reefs. Tailings, acid drainage, and increased shipping/port activity can affect coastal ecosystems and local fisheries.
• New roads, rail/ports, hydropower, and industrial estate development can open intact forest landscapes (especially in Papua and Kalimantan) to encroachment and logging, fragmenting habitats and increasing wildlife access for hunters and traders. Coastal infrastructure can degrade mangroves and seagrass.
• Peatland drainage canals, river channel alterations, and coastal reclamation change hydrology and increase fire susceptibility; mangrove conversion to ponds or settlements reduces coastal protection and nursery habitat. In freshwater systems, dams and sand mining can alter sediment and flow regimes.
• More frequent and intense marine heatwaves drive coral bleaching and reduce reef resilience; sea-level rise threatens low-lying coasts and mangroves; shifting rainfall patterns and drought elevate peat and forest fire risk (notably in Sumatra and Kalimantan), compounding haze and biodiversity losses.
• Plastic leakage and solid waste affect coasts and reefs; agricultural runoff and untreated sewage contribute to eutrophication in nearshore waters; mining-related sedimentation and heavy metals can affect rivers and coral reefs. Seasonal fire haze is also a major air pollution problem with ecological impacts.
• Hunting for bushmeat and local trade affects many taxa, including birds in Wallacea, deer and wild pigs, and threatened species in forest frontiers. In some landscapes, hunting pressure increases after roads and logging access expand.
• Indonesia is a source and transit hub for illegal trade in songbirds (notably Java/Sumatra), reptiles, and charismatic mammals. Trafficking pressures include poaching of highly threatened species (e.g., pangolins; Sumatran tiger parts) and capture of protected birds for domestic markets.
• High fishing pressure across major fisheries management areas, including reef fisheries, can reduce biomass and alter food webs. Destructive practices persist in places (blast fishing/cyanide in parts of eastern Indonesia), while bycatch affects sharks, rays, turtles, and marine mammals.
• Depletion of timber, reef fish, sea cucumbers, sharks/rays, and other high-value resources can occur where enforcement is limited and markets are strong. This reduces livelihoods and ecological resilience, especially for remote island communities reliant on coastal resources.
• Encroachment and habitat fragmentation increase conflict with elephants (Sumatra), tigers (Sumatra), and orangutans (Sumatra/Kalimantan) through crop raiding, livestock depredation, and defensive killings. Conflict is often linked to agricultural frontiers and degraded buffer zones.
• Tourism and recreation (e.g., in Komodo National Park and popular dive destinations), boat traffic, and unregulated visitation can stress wildlife and degrade habitats if carrying capacity, waste management, and zoning are insufficient. Noise and vessel strikes can affect marine fauna locally.
• Introduced rats, cats, and invasive plants can impact island endemics; invasives and disease vectors can spread via ports and inter-island transport. In freshwater systems, introduced fish can alter native communities in some lakes and rivers.
• Emerging disease risks include pathogen spillover at wildlife-livestock-human interfaces in fragmented landscapes and potential impacts on great apes from human respiratory illnesses. Aquaculture disease outbreaks can also affect coastal water quality and local economies.
• Rapid growth around major cities (e.g., Java, Sumatra coastal hubs) drives land conversion, water pollution, and demand for construction materials, and increases pressure on upstream watersheds and nearby coastal habitats.
• Small, isolated populations (e.g., Sumatran rhinoceros, some island endemics, fragmented orangutan subpopulations) face inbreeding and loss of genetic diversity due to habitat fragmentation and low numbers, complicating long-term recovery without intensive management and connectivity.