SMALL PASSERINE BIRD IN WAGTAIL FAMILY(16.5 TO 19 CMS.)WITH THE CHARACTERISTIC LONG ,CONSTANTLY WAGGING TAIL OF ITS GENUS.THE MAXIMUM LIFESPAN IN WILD IS 12 YEARS.IT HAS ALSO BEEN NOTED THAT BOTH BACK AND CHIN CHANGE COLOUR DURING THE PRE-BASIC MOULT;ALL BLACK-THROATED SUB SPECIES DEVELOP WHITE CHIN AND THROATS IN WINTER AND SOME BLACK-BACKED BIRDS ARE GREY -BACKED IN WINTER.AS MANY AS SIX SUBSPECIES MAY BE PRESENT IN WINTERING GRONDS IN INDIA.THE TERRESTRIAL AND AQUATIC INSECTS AND OTHER SMALL INVERTEBRATES FORM THE MAJOR PART OF THE DIET.THESE RANGE FROM BEETLES,DRAGONFLIES,SMALL SNAILS, SPIDERS,WORMS,CRUSTACEANS TO MAGGOTS FOUND IN CARCASSES AND MOST IMPOTANTLY FLIES ,IN THE ORDER DIPTERA.SMALL FISH FRY HAVE ALSO BEEN RECORDED IN THE DIET.