Migratory Birds in Bengal and its Problems

Migratory Birds in Bengal and its Problems

--- Dr. Debasish Mukherjee, eminent Advocate

The word 'migration' has come from the Latin word "migra" which means going from one place to another.  In birds, migration means two way journeys, i. e outward journey from home to the new places and back journey from the new places to the home. 

   According to L. Thompson, "bird migration may be described as changes of habitat periodically recurring and alternating in direction, which tend to secure optimum environmental conditions at all times". This movement occurs during the particular period of the year and birds usually follow the same route.

   The reasons for migration are:- Instinct and Gonadal changes, scarcity of food and day length, photo-periodism, seasonal variation, light etc .During winter in the northern hemisphere, several species of birds migrate generally from trans Himalayan regions and other parts of northern Asia to the wetlands of India.  They spend the entire winter at these wetlands and return with the onset of spring . In southern West Bengal, migration is generally complete by the end of December. Migratory water bird populations peaking during last week of December and the first week of January.  The migratory birds mainly concentrated in the Southern parts of Bengal e.g Saheb Bandh (Purulia), Santragachi Jheel (Howrah), Bakreswar Barrag (Birbhum), Tilpara Barrage (Birbhum), Ballavpur Wildlife Sanctuary (Birbhum), Nalban Bheri (Kolkata) and in Northern part of Bengal at Kulik (Raigunj) and Rasikbill at Coochbihar.   

      Migratory Birds face many problems e.g. storms, starvation, hunting, collisions with man-made objects like wind turbines and development of agriculture and destruction of water-bodies and deforestation.  Unfortunately, migratory birds are now more threatened species as more than 40% of the species are declining.  

   For example, Santragachi Jheel at Howrah is a Bird Watchers' Paradise in winter but the number of Migratory Birds is decreasing due to lack of maintenance of the waterbody (Jheel) and the surrounding areas.

Purulia district has several large and small water bodies having diverse aquatic flora and fauna.  The said wastelands are abode of various migratory as well as residential birds but the misfortune in respect to ecosystem is that a decreasing trend is observed that in last six years, population of migratory birds in this district have been reduced by 37%. The reasons behind this reducement are pollution, hunting, deforestation.  In Purulia most of the water bodies are surrounded by many tribal communities and to them the birds are the source of food. They are not aware of ecosystem and socio-economic impact of avian species. These problems can be solved only by awareness of the people.  

  There is another example for reduction of migratory birds at Kulik Bird Sanctuary.  The sanctuary is located 3 kms from Raigunj town having 370 acres of land. It is located on the banks of Kulik river. The migratory birds mostly from Siberia come to the sanctuary between April and May and return in December.  Recently the Forest Department has noticed a sudden drop in the migratory birds population. The reasons behind such drop are the celebrations and picnics adjacent to the sanctuary.  Thick smoke from the open air cooking drifted to the Forest , playing music loudly made the situation worse. The only solution is to declare the adjacent areas of the sanctuary as silent zone, picnics be stopped at the sanctuary to ensure that smoke does not disturb the avian population. These steps can only be taken by the local administration with the help of the Forest Department. Awareness raising plays a vital role in changing the minds and behaviours of the people and in inspiring others to take part in the movement. 

   Apart from the public awareness programmes, Government authorities should come forward to protect the migratory birds by proper maintenance of the waterbodies.  In recent times villagers of different parts of Southern Bengal also are taking the initiatives to protect the migratory birds.