"Indonesia's Wetlands: A Lifeline for Migratory and Resident Birds"

A big flock of waterbirds at the Sembilang National Park © Muhammad Iqbal image source EAAFP

*Heri Tarmizi

Wetlands in Indonesia are not only vital habitats for water birds, waders, and terrestrial species but also provide essential ecosystem services that benefit both wildlife and humans. 

 Wetlands play a pivotal role in maintaining the ecological balance of both aquatic and terrestrial ecosystems. In Indonesia, these landscapes are crucial habitats for water birds, waders, and even terrestrial species, particularly during migratory seasons. Spanning over 20 million hectares, Indonesia’s wetlands represent a unique ecosystem, essential for biodiversity, hydrological stability, and ecological services.

Wetlands as Crucial Habitats

Wetlands are dynamic ecosystems characterized by water saturation, either permanently or seasonally, which create conditions for specialized flora and fauna to thrive. For birds, especially water birds and waders, wetlands offer critical resources such as food, nesting sites, and protection from predators. These ecosystems provide diverse habitats, including marshes, swamps, peatlands, mangroves, and tidal flats, each supporting a unique assemblage of bird species.

Wetlands act as a refuge for birds, especially during migratory seasons, as they offer abundant feeding grounds. During migrations, wetlands along flyways become critical stopover and wintering sites, where birds can replenish their energy reserves for long flights. The Indonesian wetlands, due to their size and diversity, are particularly significant for migratory water birds and shorebirds.

The Role of Wetlands in Bird Migration

Indonesia is positioned along the East Asian-Australasian Flyway, a major migratory route that stretches from Siberia and Alaska in the north to Australia and New Zealand in the south. Each year, millions of migratory birds, including water birds and waders, traverse this route, stopping in wetlands across Indonesia to rest, feed, and refuel before continuing their journey. Wetlands serve as essential stopovers during this journey, offering crucial feeding grounds for species like the Bar-tailed Godwit (Limosa lapponica), Curlew Sandpiper (Calidris ferruginea), and Great Knot (Calidris tenuirostris), among others.

Migratory shorebirds and water birds rely heavily on Indonesia’s wetlands, particularly during the non-breeding season (wintering period). These birds are primarily dependent on tidal flats, salt marshes, and freshwater wetlands, where they feed on invertebrates, small fish, and other aquatic organisms. The loss or degradation of these habitats could lead to significant population declines in migratory bird species.

The Ecological Importance of Wetlands

Wetlands are not only critical for migratory species but also play an important role in supporting resident water birds and terrestrial birds. For instance, wetlands in Indonesia provide breeding and foraging habitats for species such as the Lesser Adjutant (*Leptoptilos javanicus*), Milky Stork (Mycteria cinerea), and the critically endangered White-winged Duck (Asarcornis scutulata). Additionally, terrestrial bird species often utilize wetlands for feeding and shelter, taking advantage of the diverse food resources and vegetation.

Wetlands also provide numerous ecosystem services that benefit both wildlife and humans. They regulate water cycles, mitigate floods, and store carbon, making them vital for combating climate change. Moreover, they support fisheries, agriculture, and tourism, all of which contribute to the livelihoods of local communities.

Major Threats to Wetlands in Indonesia

Despite their importance, wetlands in Indonesia face numerous threats, primarily due to human activities. The conversion of wetlands into agricultural land, urban expansion, and the development of aquaculture, such as shrimp farming, have led to significant habitat loss. Additionally, pollution from industrial and agricultural runoff, unsustainable fishing practices, and the illegal hunting of birds pose further threats to these ecosystems.

Climate change also exacerbates the degradation of wetlands. Rising sea levels, increased storm intensity, and changing rainfall patterns threaten the stability of coastal wetlands, while prolonged droughts can dry up freshwater wetlands, reducing their capacity to support bird populations. The combined effects of these threats could lead to the disappearance of critical bird habitats, which would have dire consequences for migratory and resident bird species.

Indonesia’s Five Largest Wetlands

1. Sembilang National Park  

   Located in South Sumatra, Sembilang National Park is one of the largest wetlands in Indonesia, covering over 2,000 square kilometers. It consists of mangroves, peat swamps, and tidal mudflats, making it an essential site for migratory shorebirds and water birds. The park is part of the East Asian-Australasian Flyway and provides critical habitat for species such as the Lesser Adjutant, Milky Stork, and numerous wader species.

2. Berbak National Park  

   Situated in Jambi, Sumatra, Berbak National Park spans approximately 1,600 square kilometers and is dominated by freshwater swamp forests and peatlands. It is a significant Ramsar Site (a wetland of international importance), home to several endangered species, including the White-winged Duck and Storm's Stork (Ciconia stormi). The park also provides a wintering site for migratory birds such as the Asian Dowitcher (Limnodromus semipalmatus).

3. Wasur National Park  

   Located in the southern part of Papua, Wasur National Park is a vast wetland ecosystem that spans nearly 4,100 square kilometers. This park is part of the Trans-Fly eco-region and contains a diverse range of habitats, including savannahs, swamps, and mangroves. Wasur National Park supports large populations of migratory shorebirds and is an important stopover for species such as the Great Knot and Red-necked Stint (Calidris ruficollis).

4. Danau Sentarum National Park  

   Situated in West Kalimantan, Danau Sentarum National Park is one of Indonesia’s most important freshwater wetland systems. The park covers approximately 1,300 square kilometers and consists of seasonally flooded forests, peatlands, and lakes. It is home to a rich diversity of bird species, including the Lesser Adjutant, Oriental Darter (*Anhinga melanogaster*), and the critically endangered Storm's Stork.

5. Rawa Aopa Watumohai National Park

   This national park, located in Southeast Sulawesi, covers about 1,050 square kilometers and contains vast freshwater and brackish swamp forests. It is an important habitat for resident water birds and migratory species, providing essential feeding and breeding grounds. The park is known for its populations of the endemic Sulawesi Masked Owl (Tyto rosenbergii) and the endangered Javan Pond Heron (Ardeola speciosa).

Conservation Efforts and Future Prospects

To address the growing threats to wetlands and their bird populations, Indonesia has taken several steps to conserve these critical ecosystems. The designation of Ramsar Sites, national parks, and nature reserves has provided some protection for wetlands, but enforcement remains a challenge. In recent years, there has been a push for community-based conservation initiatives, which involve local communities in the management and protection of wetlands. These initiatives often focus on sustainable resource use, habitat restoration, and awareness campaigns to reduce the pressures on wetlands.

Additionally, international collaborations through initiatives like the East Asian-Australasian Flyway Partnership have facilitated greater coordination in the protection of migratory bird habitats. However, more effort is needed to ensure the long-term sustainability of wetlands in Indonesia, especially in the face of climate change and ongoing habitat destruction.

Conclusion

Wetlands in Indonesia are not only vital habitats for water birds, waders, and terrestrial species but also provide essential ecosystem services that benefit both wildlife and humans. These ecosystems play a crucial role in supporting migratory birds during their long journeys along the East Asian-Australasian Flyway, making them key to global biodiversity conservation efforts. However, wetlands face numerous threats from human activities and climate change, necessitating urgent conservation action. By protecting and restoring

Indonesia's wetlands, and engaging local communities in sustainable management, the country can ensure that these vital ecosystems continue to provide critical habitat for birds and support biodiversity well into the future.

References

- MacKinnon, J., Phillips, K. (1993). A Field Guide to the Birds of Borneo, Sumatra, Java, and Bali. Oxford University Press.

- BirdLife International. (2021). “East Asian-Australasian Flyway.” Available at: [Birdlife]

- Ramsar Convention Secretariat. (2016). An Introduction to the Convention on Wetlands. Ramsar Convention Secretariat.

- Wetlands International. (2020). Status of Indonesian Wetlands. Wetlands International.

- Giesen, W., & Van Balen, S. (1991). “Water Birds in Indonesia: Their Status and Conservation.” Asian Wetland News , 5(2).