Migratory birds from Siberia and other cold regions have started flocking to the banks of the Karnaphuli River and the seashore in Chattogram after the onset of winter.
The hill areas, sea beach and the banks of the Karnaphuli resound to the chirping of the birds that take sanctuary here this time of year finding the area relatively less cold.
These places enriched with greeneries have turned into ideal sites for bird watching.
Bird lovers throng the seashore and Karnaphuli banks in large number, especially on holidays, to enjoy themselves watching the birds' chirpy activities and listening to their twittering.
There has been created a picturesque natural setting with the birds' taking shelter in the areas escaping extreme cold in the northern countries and in search of food.
Muhammed Majidul Alam Shourav, a resident of Patenga, said, 'Morning starts for us with hearing the sounds of migratory birds. There move a large number of birds in our village, it being very close to the Karnaphuli river."
"Migratory birds also haunt fishermen village in Katgor area," he a added.
Razia Sultana, a zoologist and bird lover, said, "Every year during winter, when cold turns severe, migratory birds flock to the seashore and the banks of the river Karnaphuli in Chattogram from Siberia, China and Himalayan countries during December-January period."
Nature takes different form due to presence of the huge birds here and there in Chattogram, she added.
Many of the city dwellers visit the riversides enjoying the birds' frolicking.
There has not been taken any effective step so far from the administration or Chattogram Port Authority for protection of the foreign feathered friends in their sanctuaries, lamented a few city dwellers.
On the other hand, poachers are prowling through the guest birds' sanctuaries putting their existence under threat.
They sell birds after hunting at the local markets in Anwara, Paitya and Boalkhali upazilas.
Besides, some poachers carry birds to their homes for selling those to their neighbours.
The climate of Bangladesh during the short spanned winter provides an ideal environment for these migratory birds.
Migratory birds are very colorful. These exotic birds add to the natural beauty of rivers and lakes of Bangladesh.
According to sources, migratory birds coming from the coldest parts of the Central Asia settle down in the watery marshlands, forests, and plains near the rivers of Bangladesh, and other nearby South Asian countries because of the warm weather, abundance of fresh water, and food.
This event has been taking place in nature for tens of thousands of years.
Migration is critical for survival of several species of birds that make this journey every year.
Most bird species are precise in following their migration calendar. Several factors influence the length of migration- how far they fly depends on the time taken for the journey, the amount of time it takes to produce healthy brood, and amount of nurturing their young need, experts opined.
The greatest mystery lies in the birds' ability to navigate accurately across the states.
Many scientists believe that natural magnetic sensors in their brains, eyes, and bills help them sense the Earth's magnetic fields, and so they can sense the north and south directions as they fly. Some birds also learn these routes from their parents.