Historically, birds migrate, but they do so more in search of food and warmth. Traditionally, Pallikaranai wetland plays a major role in migration, and is home to 70% of migrants, between November and May. Pulicat Lake, that straddles Tamil Nadu and Andhra Pradesh, and is the second largest lagoon (brackish water) welcomes over 80 per cent of migratory birds.
Come migration season, and people immediately think of flamingos. It is common to spot them from the roads in Sulurpet (Andhra Pradesh). However, thousands of them arrive in the Tamil Nadu side of Pulicat, after February. They make their homes in the Annamalaicherry in Pulicat, at the confluence of sea and fresh water. To spot them , one has to go down the lake on a boat.
Unscientific estimates say that 15 years ago, over 1. 5 lakh flamingos used to arrive from the Rann of Kutch in November. They were found moving across Tamil Nadu in the two to three months that they spent here. Due to habitat loss, the numbers have come down to 50,000 in the last few seasons.
However, the flamingos are not the only ones to have caught the attention of bird watchers this year. The biggest and happiest sighting this year has been of the Amur falcons. Between 150 and 200 Amur falcons have been sighted this year, and they have been spotted in Tirunelveli, at the Koonthangulam bird sanctuary. They fly in from Africa and Russia in lakhs. Until a few years ago, people in parts of Nagaland used to spread a net across their waterbodies, trap these falcons and eat them. Thanks to conservation efforts, the trapping has stopped and the birds fly free. However, this is the first time in recent history that they are known to have flown this far south.
Interestingly, what has attracted them to Tirunelveli is the severe drought conditions at the Vijayanaryanapuram lake. The river bed is completely dry, laying bare a number of insect species for the Amur falcons to feed upon, thanks to the drought.
On the other hand, Cyclone Vardah that passed through Chennai, saw a number of changes in the arrival of winged visitors. Bridled terns, normally spotted mid-sea, were seen in Pallikaranai, for well over two weeks. Post- Vardah, we also saw an abundance of waders like red knot, plovers and sandpipers in Pulicat. It is suspected that climate change and vagaries of weather are the reason for the unusual sightings. In Kancheepuram, we have spotted the Serpent eagle and other birds usually seen only in the Western Ghats.
However, more scientific studies are required to establish the migratory patterns. Tamil Nadu and Andhra Pradesh should pro-actively apply for Ramsar rating. Till date, the state has only one Ramar rated spot, which is Point Calimere. Ramsar is a globally recognised rating and it comes with immense benefits. It is extremely important to get this rating for development and conservation activities. Already, we are seeing the effect of over exploitation of our water bodies through over fishing, real estate development activities and shrinking of farm lands.
The migratory season is coming to an end. But our studies should continue. —The writer is Founder, The Nature Trust
Migration is the seasonal movement of populations from one geographic location to another. Birds fly such great distances to take advantage of seasonally abundant food and to avoid places where food and other resources are scarce.
Ninety per cent of migrating birds fly at airspeeds between 25-70 kilometres per hour. The speed and direction of the wind influence their travels. Shorebirds fly 3 -65 kms/hr, waterfowl 5080 kms/hr and raptors 30-70 kms/hr.
A one-way migration can take anywhere from several weeks to 4 months. Birds have an internal clock to alert them on when to migrate. A oneway migration can take anywhere from several weeks to 4 months.
Out of over 2000 species in Asia and sub-species, about 350 are migrants. In the subcontinent, a majority of migratory birds are winter migrants.
Migrants may be indicators of the health of our environment. If their populations continue to decline, our quality of life declines with them.
Image Courtesy: KVRK Thirunaranan