Avian Diversity :- Tremendous work has been done on various aspects of avian diversity across the worlds ( ali 1941 ; fleming , 1968 ; overtone , 1972 ; tekke, 1972 ; vemon and martin, 1975 ; parke's , 1975 ; pearson , 1975 ; norse and mcmanus , 1980 ; woodcock, 1980 ; fanned, 1981 ; spina , 1982 ; ali and ripley , 1983 ; hussain et al, 1984 ; brichetti and massa , 1984 ; grinnell , 1990 ; billy et al, 1992 ; sibley and munroe , 1993 ; gill, 1995 ; andrews , 1996 ; raja et al, 1999 ; rahbek and graves, 2001; anderson and baldock , 2001 anderson and baldock , 2001 azam and shafique , 2005 ; kumar et al, 2006 ; surana et al. 2007 ; lepage , 2008 ; bahadauria et al, 2012 bibi and ali , 2013 soka et al, 2013 .Birds occur on land, sea and freshwater, and in virtually every habitat, from the. Lowest deserts. To the mountains. Our knowledge of bird species can tell us a great deal about the state of the world and wider biodiversity. Patterns of bird diversity are driven by fundamental biogeographic factors, with tropical countries supporting the highest species richness. (Bird life international, 2013 ) mayer ( 1935 ) estimated 8500 . Species of avian fauna belonging to 2600 genera throughout the world. REVIEW OF LITERATURE 2