The White-winged Wood Duck (Cairina scutulata) listed as Endangered in The IUCN Red List of Threatened Species, inhabits stagnant or slow-flowing natural and artificial wetlands inside or adjacent to evergreen, deciduous or swampy forests.
In the 90s, WWF started a project on the conservation of these ducks.
Thirty years later, the Forest Department of the Indian state of Assam now relies on Czech Republic’s Zoo Zlin – where dozens of these shy ducks are currently housed – for conservation breeding of the State Bird owing to a rapidly declining population across its range.
The decline of the bird has largely been attributed to “widespread loss, degradation and disturbance to riverine habitats.”
The White-winged Wood Duck had been the targeted species for conservation behind the Protected Area status to Dibru-Saikhowa National Park known for its rich birdlife.
“Many wetlands inside Dibru-Saikhowa have now been lost. Wetlands inside the Park that were once the breeding ground for the Spotbilled Pelican could not be found now,” said renowned ornithologist and author Anowaruddin Choudhury.
“The sharpest decline has been in the numbers of the Spotbilled or Grey Pelicans Pelicanus philippensis philippensis. The reasons are human disturbance in nesting and roosting areas and decline in fish availability. Along with the loss and degradation of wetlands, populations of many water birds–both resident and migratory – are declining fast,” he said.
Drying and formation of wetlands are natural process, but the rate at which wetlands are drying up is alarming. The gap has been widened forcing many of the wetland-dependent species to the edge.
A sharp fall in the number of migratory waterbirds even inside Protected Areas has been a warning that wetlands in this Himalayan valley are drying faster than before.
Wetland habitat of rare bird imperiled by infrastructural projects
A number of factors have been responsible for the rapid decline in wetland ecosystem that include urbanization, siltation, overfishing, human interference, land and water grabs, decrease in freshwater inflow, choking of lagoon mouths due to silt
deposition, fragmentation and degradation of habitat, environmental contaminants, hunting, land use patterns, changes in aquatic vegetation, pollution and development projects.
There is a large network of sites that the birds depend on for migration and the loss of these sites makes the visitors vulnerable.
Migratory waterbirds – ducks, geese and swans, cranes and rails, storks, ibises and spoonbills, flamingoes, gulls, terns, skimmers, pelicans, grebes, cormorants, herons and egrets, gannets, divers, waders, tropic and frigate birds – ecologically dependent on wetlands for at least a part of their annual life cycle.
The survival of the Critically Endangered White-bellied Heron Ardea insignis, one of the 50 rarest birds in the world and the Black-necked Crane Grus nigricollis depend largely on the wetland habitat.
“The White-bellied Heron has become extinct in Nepal and only 6 have been found in India,” said Dr Himadri Sekhar Mondal, Scientist-A with the Bombay Natural History Society after his team recorded the first nesting site in the Namdapha Tiger Reserve in Arunachal Pradesh.
The Black-necked Crane’s presence at Nyamjang Chuu in Arunachal had led to the scrapping of a 780 MW hydropower project – one of 13 proposed hydropower projects – in Tawang, Arunachal.
“In 2018 the NGT suspended the environment clearance given to the Nyamjang Chuu project after the Wildlife Institute of India’s report,” revealed Malyashri Bhattacharya, associated with the WII study.
Hydropower projects built over rivers originating in the Tibetan Plateau dried up many wetlands pushing breeding habitats of rare birds to the brink.
Importance of the Brahmaputra floodplain wetlands
The Brahmaputra valley has a distinctive natural environment that depends largely on wetlands. The innumerable freshwater lakes (locally called beels), ox-bow lakes, marshy tracts and thousands of ponds and tanks used to hold water almost throughout the year and are vital to water needs and food production.
Besides, these serve as the habitat for thousands of species of flora and fauna. Protected Areas along the Brahmaputra include the Dibru-Saikhowa National Park, the Kaziranga National Park, the Laokhowa-Burhachapori Wildlife Sanctuary, the Pobitora Wildlife Sanctuary and Orang Tiger Reserve.
With a network of connecting streams and small rivers that run from the hills, through the forest and then to the Brahmaputra – each also form an ideal habitat for water birds both – resident and migratory.
From the marshes of Kaziranga, Neemati, Majuli, Dibru-Saikhowa, Joysagar, Maguri or the Panidihing Bird Sanctuary to Deepar Beel in Guwahati – birders delight at the blissful sight of thousands of teals and ducks’ ‘pseudo sleeping’! Pintails, Mallards, Shovellers and Pochards, Gadwalls jostle to give them company.
Lesser Whistling Ducks, Spot-billed Ducks, Greylag, Ruddy Shelducks, Wigeons and Bar-headed Geese complete the picture.
Anowaruddin Choudhury also recounted the water birds once common to the Brahmaputra Valley, “Spoon-billed Sandpiper sightings were recorded in Assam’s Sivasagar district but there have been no sightings in recent times. Sightings of the Dunlin from the wetlands of Subansiri in Lakhimpur district become rare. Many birds changed destination since the construction of hydropower projects in the area as many wetlands have dried up,” he informed.
A paper published in the journal Forktail by Maan Barua and Pankaj Sharma recounts the sightings of the Nordmann’s Greenshank, Terek Sandpiper, Red-necked Phalarope and Black-bellied Tern – none of which could be found in recent surveys inside the Kaziranga National Park.
Other important species that show drastic decline are the Critically Endangered Baer’s Pochards, Tufted Ducks, Common Pygmy Geese, Falcated Ducks, Garganeys, White-fronted Geese, Marbled Teal and Ferruginous Duck.
The Ruddy Shelduck is one of the important species of conservation concern. Although the Bar-headed geese have been in no immediate danger but recent years saw their population adversely affected by hunting and habitat destruction.
Over the last two decades, wetlands are found to be drying up within two or three months after the southwest monsoon.
Heavier rainfall on fewer rainy days, as an effect of climate change, results in flowing down of the rainwater rather than percolating underground. Moreover, with the increase in temperature evaporation also increases that lead to depletion of surface water level resulting in depletion of aquatic life and vegetation cover.
Assam Remote Sensing Application Centre has identified 3,513 wetlands in the state – about 9.74 per cent of the state’s area – varying from 2.50 ha to 882.50 ha of areal coverage. The state’s natural wetlands, swamps or marsh have a share of 42.9 per cent.
Assam comes seventh in terms of the area covered by wetlands, while it tops the list when it comes to freshwater wetlands in the whole of India – according to the study Ardrabhumi Aru Asom (Wetlands and Assam) by Prof Kaliprasad Sarma of the Department of Environmental Science, Tezpur University.
But many are drying out, getting silted over or being encroached upon; some 1,367 are facing serious threats to their existence. The most rapid has been the decline in natural wetlands, the study found.
Large-scale fragmentation wetlands show an increase in their number but turned out to be less favorable as wintering sites for migratory birds.
“The last waterfowl survey in the Pobitora Wildlife Sanctuary in January found some 15,000 water birds. Of them 64 were wetland-dependent species,” said Range Officer Mukul Tamuly.
“Shrinkage in wetlands due to siltation has become a grave concern. Within the Sanctuary, 50 per cent of the natural wetlands have already dried up,” the officer said.
“Heavy shrinkage has been witnessed to large wetlands like the Tamuliduba, Hanhchora, Pagladuba while comparatively smaller wetlands like Golduba, Lambaduba have almost dried up,” he added.
In Kaziranga, drying up of wetlands has led to an increase in areas of tall grass and a reduction in areas of short grass. This gradual change will have important ecological implications in the future, experts warned.
With wetlands becoming shallow, the capacity of floodwater storage has also decreased. Experts often propose dredging as an option for some heavily silted wetlands that could help flood and erosion mitigation and keep their ecological character alive.
Poor governance key to loss of important wetlands areas
India’s rules on wetland conservation which were revised in 2017 delegated power to the state governments.
“As per the Wetlands (Conservation and Management) Rules, 2017 many states have now State Wetland Authority (SWA) and SWA needs to prepare a list of all notified wetlands and those to be notified. Further states need to prepare a digital inventory of wetlands within their jurisdiction. But here, in Assam, required leadership of state government not emerging“, said Dr Pradip Sharma, who taught Geography in Cotton College.
Large wetlands like Bosolla, Sorusolla, Silsaku, Chapaidang cease to exist under heavy encroachment while Doboka, Khamranga, Rahumari, Goraimari are imperiled by increased siltation from surface run-off and agriculture expansion in Assam’s Kamrup district.
Wetlands degradation in the Kamrup and Nagaon districts threatens the existence of the Greater and Lesser Adjutant Storks. Assam houses 70-80 per cent of the Greater Adjutant Stork.
Deepor Beel – Assam’s only Ramsar site that hosts the bird has been under constant threat from overfishing to encroachment to challenges of rapid urbanization and pollution.
A part of the Dibru-Saikhowa Biosphere Reserve, Maguri Motapung Beel is an Important Bird and Biodiversity Area. Overfishing, siltation and oil exploration in the vicinity pose a constant threat to the wetland.
“Rooted in role of wetlands as ‘biodiversity hotspots’ for migratory birds, in our country conservation plans have largely been dominated by Protected Area based approaches. But there are vast swathes under periodic use by migratory species that fall outside Protected Areas,” says Dr Sidharth Kaul, president, Wetland International South Asia.
On the ground, there has been a total lack of monitoring or managing wetlands outside Protected Areas.
There are key links between migratory bird conservation and local community development.
Connecting people at key migratory bird sites, reinforcing education and awareness about the need to protect migratory birds and their habitats they rely upon, have become very urgent to balance the needs of conservation against the needs of local communities living around wetlands.
After all, all the birds too need a safe place to rest, feed and raise a family!