HERI'S BIRDSCAPE INSIGTH

 *Heri tarmizi

The Quiet Migration of Asian Openbill Storks

For years, the Asian Openbill Stork (Anastomus oscitans) was little more than an occasional surprise for birdwatchers in Aceh. A lone individual in Langsa, a pair resting briefly in Pidie, or a fleeting silhouette over rice fields in Aceh Besar—interesting, but rare.

From Scattered Sightings to Something Bigger

Between 2023 and 2024, records of Asian Openbill Storks along Aceh’s east coast remained modest. Most observations involved only one or two birds, scattered across regions such as Langsa, East Aceh, North Aceh, Pidie, Aceh Besar, and Banda Aceh. At the time, it was easy to assume these birds were simply passing through—brief visitors on a longer journey.

But by October 2025, something different was unfolding.

Local residents in Gampong Cadek, a village about three kilometers from the eastern coastline of Aceh Besar, began noticing large white birds gliding in from the direction of the Malacca Strait. Videos shared by the community revealed an extraordinary scene: hundreds of Asian Openbill Storks, soaring together, riding thermals, and moving inland.

Riding the Wind, Finding the Land

Not long after, similar behavior was observed in Montasik, where around 80 individuals were seen soaring above agricultural landscapes. These were not random movements. The birds appeared confident, purposeful, and well-adapted to the air currents—a reminder of how skilled large waterbirds are at reading the sky.

Then came the floods.

Following the major flood on 26 November 2025, Asian Openbill Storks were recorded again in Samahani, Aceh Besar. This time, they were not just flying overhead. They were feeding and resting in flooded rice fields, forming loose flocks numbering in the dozens.

For a species closely tied to wetlands, this made perfect ecological sense.

Rice Fields as Wetlands

Asian Openbill Storks are waterbirds in the truest sense. Their survival depends on shallow water habitats where prey especially aquatic snails is abundant. While natural marshes and swamps are ideal, flooded rice fields often function as substitute wetlands, especially during the rainy season or after floods.

In Aceh, damaged landscapes can quickly become feeding opportunities. Where water lingers and snails thrive, openbills follow.

Asian Open-billed strok photo By Zulfikar

What the Asian Waterbird Census Revealed

To better understand these changes, conservation groups including KSLH-Aceh, Let’s Birding Sumatra, and Aceh Birds Club carried out surveys as part of the Asian Waterbird Census (AWC) 2026.

On 30 January 2026, surveys in the Lambada coastal area of Aceh Besar recorded around 100 Asian Openbill Storks. The birds were first seen soaring and gliding, before settling into nearby mangrove areas to rest and feed.

One detail stood out: about a quarter of the birds were juveniles. Their softer grey plumage made them easy to distinguish from adults. This suggests that the movement into Aceh was not limited to older, experienced birds—it involved younger individuals as well.

The following day, surveys along the eastern coastline of Aceh Besar, Pidie, and Pidie Jaya found 14 Asian Openbill Storks in Laweung, Pidie, feeding in rice fields alongside resident species like the Intermediate Egret. These mixed gatherings often signal productive feeding conditions.

Bird observation photo by Sofyan

Birds, Farmers, and an Overlooked Partnership

Asian Openbill Storks are sometimes misunderstood. Yet in rice-growing regions, they play an important ecological role. Their diet is dominated by aquatic snails—some of which are well-known rice pests.

During the AWC activities, survey teams spoke with local farmers about the benefits of waterbirds as natural pest controllers. Protecting these birds is not only about conservation—it can also support more sustainable farming by reducing dependence on chemicals.

Why Now? Some Early Thoughts

So why did Asian Openbill Storks suddenly appear in such numbers?

One possibility lies in weather patterns over the Malacca Strait. In late 2025, unusual storm systems and cloud formations were reported in parts of the region. Large birds are highly sensitive to wind, thermals, and atmospheric stability. Safer air corridors—such as routes from mainland Southeast Asia toward Sabang and Aceh Besar—may have become more attractive.

Another likely factor is habitat loss elsewhere. Floods and landslides in areas like Pidie Jaya, Bireuen, North Aceh, East Aceh, Langsa, and Aceh Tamiang damaged rice fields and aquaculture ponds. When feeding sites disappear or become unsafe, waterbirds do what they have always done: they move.

A Message Written in Wings

The sudden presence of Asian Openbill Storks in Aceh is more than an exciting moment for birders. It is a message from the landscape itself.

For scientists, it signals shifting migration and movement patterns.
For policymakers, it highlights the value of wetlands—both natural and agricultural.
For communities, it shows that healthy ecosystems bring unexpected allies.