Asian waterbird census data causes mixed feelings

Evaluation of the bird data picked up from the Asian Water bird Census (AWC) held between 1987 and 2014 was recently carried out by the Kerala scientists.

The annual census, coordinated by Wetlands International, also happens to be the first country-wide citizen science activity on natural history in India.

Researchers focused their attention on the data generated from the four Ramsar sites of Kerala- Sasthamkotta Lake, Ashtamudi Lake, Vembanad Lake and Kole Wetlands – and also the other important wetland habitats to get a bird’s eye view of the population trends of wetland avian fauna.

Highlights:

• The brightly coloured purple swamphen is one species that have thrived amidst widespread destruction of its habitats. Its population trend analysis demonstrated that the species has increased in Kerala during the last decade.

• The painted stork, earlier evaluated as a vagrant visitor to wetlands of Malabar and south Kerala has spread beyond the region they are generally found.

• The population of Asian Openbill, extremely rare during the 1970s, has remarkably increased since 2001, with at least four census reporting the presence of more than 3,000 birds. So is the case of Eurasian spoonbill as there have been several reports of sighting of large flocks from Kole Wetlands, Vembanad Lake and Kuttanad Wetlands. Same is the case with black headed Ibis.
• Indian spotbilled duck, glossy ibis, oriental darter, Asian woollyneck and spot billed pelican recorded increased presence whereas the population of the river terns and cormorants remained stable.
• But the bird group of terns underwent a steady decline over the years. From the nearly 30,000-strong population in 1993-94, it had plummeted to just near 10,000 in the last      decade. The loss of estuarine habitat like Purathur in Malappuram district and disturbances in other estuaries might have contributed to this decline. The decline was evident in the relatively stable sites such as Kole Wetlands, rued the ornithologists.
• The population of whiskered tern, which form the major chunk of the population of the terns in the State, too has fallen significantly. Gulls too painted a gloomy picture as they were sighted in lesser number during the past few censuses.
• The BirdLife International has recorded that 11 water bird species of Kerala come under the IUCN Red list threatened categories with the black bellied tern being one of the ‘Endangered’ waterbird species in Kerala. The only report of black bellied tern during AWC was from the Kole Wetlands.
• Great knot, a ‘vulnerable,’ trans-continental migrant, has been reported from four sites whereas the Asian woolly neck stork (another vulnerable species), has been reported from 44 wetlands across the State.
• An influx of Eurasian coot, which was an added to the list of Kerala birds during the late 1980s, has been reported in the State during winter season.

The report has identified the following threats:

Demographic pressure, industrial development, pollution, urbanisation, agriculture and aquaculture and water transport have been adding pressure on the wetlands of the State.

Reclamation of wetlands and the aquatic ecosystems, which are often considered as wastelands, is spelling trouble to several taxa. The stake nets used for fishing removes a wide array of non-target organisms, which are functionally important to the aquatic environment. Destructive fishing practise are also taking a toll on the bird population, it was reported.

Unregulated fishing, reclamation of wetlands, dumping of solid waste and domestic sewage too posed threats to the wetlands of Kerala, according to ornithologists.

About AWC:

Asian Waterbird Census is an annual event in which thousands of volunteers across Asia and Australasia count waterbirds in the wetlands of their country. This event happens every January. This event is coordinated by wetalands International and forms part of global waterbird monitoring programme called the International Waterbird Census (IWC).

• Asian Waterbird Census (AWC) was started in the year 1987. Its main focus is to monitor the status of waterbirds and the wetlands. AWC also aims to create public awareness on various issues concerning wetlands and waterbird conservation. Each year the census is carried out as a voluntary activity.
• 2016 marks the 50th global International Waterbird Census (IWC). With this, it has become the world’s longest running biodiversity monitoring programme. 2016 also marks the 30th year of AWC.
• In India, the AWC is annually coordinated by the Bombay Natural history Society (BNHS) and Wetlands International.

What are waterbirds?

According to Wetlands International (WI), waterbirds are defined as species of birds that are ecologically dependent on wetlands. These birds are considered to be an important health indicator of wetlands of a region.