Kolkata may have lost one of its winter signatures, migratory birds at Alipore Zoo, almost a decade ago. But forest officials and bird-lovers have something to rejoice. The population of winged guests in winter seems to be rising steadily at Santragachhi Jheel in Howrah over the past few years.
“A rough estimate of the bird population at Santragachhi Jheel every winter has revealed that their number has gone up by at least three times since 2009. The census is done in January each year. It is good news for us all and shows that our efforts have started paying,” M Rahaman, divisional forest officer of Howrah, said.
This year, bird-lovers and members of the NGO Prakriti Samsad, which conducts the census, spotted about 7,300 birds at the jheel. In the last data available with the Howrah forest division in 2009, the bird population was about 2,500.
“Such species as the Lesser Whistling Duck ( Chhoto Saral), Gadwall ( Peeing Hans), Common Teal ( Patari Hans), Northern Pintail ( Dig Hans) and Indian Commorant ( Pankouri) were found in large numbers and comprised a majority of the population,” Kushal Mookherjee, vice-president of Prakriti Samsad, said. On the other hand, the water body inside Alipore Zoo, earlier a haven for migratory birds from the Central Asia and Manas Sarovar areas drawing thousands of bird lovers even until the late-’90’s, now stands abandoned and not a single migratory duck has come there since 2000.
Even though no specific study was conducted to ascertain the exact reasons, experts believe that a combination of several factors, such as rising pollution and a proliferation of highrises and mobile towers, have led to the loss.
“The concretization of the banks of the zoo’s water body could also be one of the reasons. Some of the species that usually form the prey base of birds vanish when mud banks are concretized. The sounds and activities of the masons also scare birds away,” Pranabesh Sanyal, former head of the state forest department, said.
Forest officials of Howrah, however, had been renovating Santragachhi Jheel every year and weeding the waters and bed just before winter. Temporary islands have also been constructed in the middle of the jheel where water birds can roost.
The size of the jheel — around three times that of the zoo water body — could also be a great attraction for the birds. While the zoo water body sprawls over an area of about four hectares, Santragachhi Jheel is nearly 12 hectares. “Awareness building among local residents and creating a good ambience for the birds may have led to the rise in their numbers over the years. Poaching of birds near the jheel has been completely stopped,” Rahaman added.
A section of the experts claimed that Santragachhi once used to boast of many more birds which flocked the water body in their thousands. Over the years, their numbers dwindled because poaching took a heavy toll. Now, they are again on the rise since poaching has stopped.
Mookherjee, however, said that, unlike tiger, lion, elephant and rhino census, this was just a rough, unofficial estimate based on bird sightings on a single day. It is very hard to count birds and there is hardly any scientific method with which their exact numbers could be ascertained. Besides, the numbers may vary from day to day. “In 2011, the population suddenly shot up to more than 10,000… we’re still not sure why. No study’s been done,” Rahaman added.