Erratic monsoons, prolonged dry spells and rising temperatures are altering the shallow wetlands Painted Storks need for feeding and breeding, exposing colonies across South Asia to growing climate pressure.
With their bright pink feathers, black-and-white wings and long yellow bills, Painted Storks are among South Asia’s most recognisable waterbirds. But the wetlands that sustain them are becoming increasingly unpredictable as the climate warms.
Painted Storks (Mycteria leucocephala) usually feed in shallow wetlands, flooded farmland and irrigation channels, sweeping their partly open bills through the water to catch fish and other aquatic prey. Bangladesh is among the countries within the species’ range. Although the bird is currently classified globally as Least Concern, its dependence on suitable water conditions leaves individual colonies vulnerable to environmental disruption.
The greatest climate threat may come from changes in the timing and availability of water.
A study of 1,095 Painted Stork nests in northern India found that nest survival was significantly influenced by annual rainfall and minimum winter temperatures. Rainfall affected whether suitable feeding wetlands remained available near breeding colonies, determining how easily adult birds could find enough food for their chicks.
The findings show why increasingly unstable rainfall can create problems for the species. When rains arrive late or wetlands dry too quickly, adult storks may have to travel farther to find fish. Longer journeys require more energy and can reduce the frequency with which parents return to feed their chicks.
Too much water can also cause difficulties. Painted Storks are specialised shallow-water feeders. Intense rainfall and flooding can suddenly deepen wetlands, disperse prey and make fish less accessible. Storms may also damage nesting trees or disturb breeding colonies.
The Intergovernmental Panel on Climate Change projects that heavy and intense rainfall will become more frequent across South and Southeast Asia. South Asian summer monsoon rainfall is also expected to intensify, although the scale and geographical pattern of the changes will differ between locations.
This means Painted Storks could face alternating periods of excessive water and severe scarcity rather than the relatively predictable seasonal wetland cycle around which their feeding and breeding behaviour evolved.
Extreme heat presents another challenge, particularly during the breeding season when adult birds must remain exposed on open nests.
Painted Storks use several natural cooling techniques. They spread their wings and wet their legs with excreta, allowing evaporation to reduce body temperature—a behaviour known as urohidrosis.
A 2024 study of nesting Painted Storks in Delhi found that temperature, humidity and wind speed significantly affected their cooling behaviour. The birds performed more wing-spreading and urohidrosis during the hottest hours of the day and during the warmer part of the nesting season.
These behaviours demonstrate the birds’ ability to cope with heat, but they also reveal their exposure. Adults guarding eggs or chicks cannot always leave their nests to seek shade or water, particularly when their partners are away searching for food.
As extreme heatwaves become more frequent in Asia, nesting birds may have to spend more time and energy regulating their body temperatures. The IPCC says extreme heatwaves will very likely increase across Asia, with large parts of South Asia expected to experience dangerous heat-stress conditions.
Climate change is not acting alone. Wetland encroachment, water extraction, pollution, fishing pressure and the removal of large nesting trees are already reducing habitat quality in many parts of South Asia.
Under such conditions, even a species with a relatively wide range can suffer local declines. A colony may disappear when a wetland dries, becomes polluted or loses its nesting trees, even while the species remains secure at the global level.
There is also evidence that restoring wetlands can bring the birds back. Painted Storks successfully established breeding nests at Chennai’s restored Adyar Eco Park, where conservation work revived native vegetation and wetland habitat. The return demonstrated that protected feeding grounds and secure nesting trees can help colonies recover.
Conservationists say protecting Painted Storks will therefore require more than safeguarding the birds themselves. Authorities must maintain natural water flows, prevent wetland filling and pollution, protect nesting trees and ensure that shallow feeding areas remain available throughout the breeding season.
The future of the Painted Stork may ultimately depend on whether South Asia can protect its wetlands while adapting them to a climate increasingly defined by heat, drought and extreme rainfall.
The following video is in Bangla:
