The disappearance of Sandwich Tern, one of the unique migrant bird species found in the Kadalundi Vallikkunnu Community Reserve, from the Kadalundi estuary over the past couple of years has raised concerns about the changes taking place to the ecology of the sanctuary.
A team of scientists led by M. Nasser, associate professor at the Department of Zoology, Calicut University, has begun a study into the disappearance of the Sandwich Tern, a migrant bird locally known as Kadalundi Aala.
The tern got the name Kadalundi Aala after birdwatchers P.K. Uthaman and L. Namasivayam reported their sighting in large numbers at Kadalundi in the early 1990s.
Although found in large numbers at Kadalundi during the wintering season in the 1990s and 2000s, the Sandwich Tern began to gradually disappear after 2007. “I have not found a single one at Kadalundi over the last three years during my observations,” said K.M. Arif, who has been studying the habits of shorebirds reaching Kadalundi for seven years.
Mr. Arif and his research supervisor P.K. Prasadan from Mary Matha College, Mananthavady, have offered their help to Dr. Nasser to study the ecological changes taking place at the Kadalundi estuary.
“We believe there is a major factor which has driven the Sandwich Terns from Kadalundi. It can be the change in food availability, or something else, which should be found out through studies,” said Mr. Arif and Dr. Prasadan.
But, interestingly, the Kadalundi Aala is now found at places such as Manjeswaram and Kannur. Birdwatcher P.C. Rajeevan has reported sighting of the Sandwich Tern at some parts of northern Malabar.
“What we don’t know is the ecological changes that have driven the Sandwich Tern from Kadalundi, which is perhaps the single most important wintering station on the west coast of India for migrant birds from colder regions of the world,” said Dr. Nasser.
The uniqueness of Kadalundi not only as a wintering station but also as a sanctuary was established with the sighting of dozens of migrant bird species by scientists and birdwatchers over the last three decades. Mr. Arif, who dedicated the last seven years for research at Kadalundi, alone identified 31 species of shorebirds, six species of gulls and 11 species of terns among the winged visitors reaching the sanctuary.
Among the specialist groups of shorebirds found at Kadalundi were Curlew Sandpiper reaching the sanctuary by October-November and departing by February-March, and Great Knot arriving by November and leaving by January mid.
Great Knot is shorebird classified as vulnerable species by the International Union for Conservation of Nature.
Source:The Hindu,5 June 2013