Threat to bird migration in Kerala

By C.V. Gopalakrishnan 

(This article appeared in The Hindu - SEPT.  7) 

Predatory fishing and the heavy use of pesticides pose a big threat to bird migration from all over the world to the wet-lands of Kerala says the latest study on the structure and species composition of wetland birds in the Kole lands of Thrissur carried out by the Division of Wildlife Biology, Kerala Forest Research Institute, Peechi Thrissur. ("Kole", refers to the peculiar type of cultivation carried out during December to May.)  

Bird migration has effectively controlled insect pests and their droppings and brought about big improvement in soil fertility. Trans-continental  species  of birds migrating to Kerala number as many as 44. They include Masked Booby, White and Black Stork, Common and Blue-winged Teal, Pale, Pied and Western Marsh Harriers, Eurasian Sparrow Hawk, Mongolian Sand Plover Blacktailed Godwit, Terek, common and other species of Sand pipers, Yellow-legged,  Brownheaded and Blackheaded Gull,  Desert  Wheatear,  Citrineand Grey wagtail. 

Kole wetlands spread over an area of 11,000 hectares in Thrissur and Malappuram districts extending from the northern banks of Chalakudi river to the southern banks of Bharathapuzha River in the North. Kole wetlands are an ideal habitat for migratory and resident birds especially for the winter visitors. The total number of birds counted during a one-year period in four intensive areas of Arimpur, Kanjany, Enamavu and Parappur varied widely from 8 to 4,993 in a month. The status of birds covered by the study ranged from aquatic feeders, insectivores, granivores, nectar and frugivores carnivores and omnivores and the count included both resident and migratory birds. 

The study has recommended that the Kole lands of Thrissur should be declared a protected area and an effective implementation of such declaration would save the migratory birds from indiscriminate poaching.  It says that fishing which is a daily activity carried out with the use of nets of very small size targeting even the tiniest fish effectively checks the foraging by wetland birds. The other major problem which may eventually lead to the ending of Kerala as a destination point for the winter migration of birds is the hunting of the birds with guns. The fire created by farmers during summer months is reported to have destroyed the nests of weaver birds, tailor birds and warblers.  

Wetlands of Kerala are on the central Asian-Indian Flyway which requires protection with the highest priority. The method adopted for the total bird census was with the identification of representative blocks and a spotting scope was used for counting the birds.     

The birds were identified by using physical features with the help of field guides and the books of Salim Ali and S.D. Ripley.  

Mr. C. Sivaperuman and E.A. Jayson authored the present study.