below information refers to the mainland india, i.e., excluding andaman, nicobar and other islands.
mainland india holds 1222 species of birds from 100 families.
though the region is not most species-rich globally, it is perhaps family-richest, an equally important aspect of avian diversity.
an attempt to share a few aspects of this richness from a threat-to-extinction point of view.
largest bird family - timaliidae (babblers)
second largest - turdidae (thrushes)
third largest - sylviidae (old world warblers)
fourth largest - accipitridae (hawks, eagles)
number of bird families for which there exist only one species or only one species occur in india - 21
number of bird families for which not more than five species exist or occur in india - 50
number of families that contain at least one endemic species - 20.
family consisting of maximum number of endemic species - timaliidae (babblers, 9 species)
5 species out of above 9 are threatened or near-threatened.
percentage of bird species threatened - 12.86 (127 out of 1222)
bird family with largest number of threatened (or near-threatened) species - accipitridae (hawks, eagles, 16 species out of 50)
second largest - scolopacidae (sandpipers, snipes, phalaropes, 14 species out of 42), and phasianidae (pheasants, partridges, turkeys, grouse, 14 out of 43)
third largest - timaliidae (babblers, 13 out of 118)
number of bird families with not a single threatened species - 54 (54%)
number of bird families with either zero or one threatened species - 76 (76%)
52% of the threatened bird species belong to the following bird families -
accipitridae (hawks, eagles),
scolopacidae (sandpipers, snipes, phalaropes),
phasianidae (pheasants, partridges, turkeys, grouse),
sylviidae (old world warblers)
anatidae (ducks, geese, swans)
above mentioned families contain 37.7% of the total species
most threatened or near-threatened bird families -
hydrobatidae (northern storm-petrels)
largest family with not a single species threatened - cuculidae (cuckoos)
second largest - alaudidae (larks)
third largest - sturnidae (starlings) and rallidae (rails, gallinules, coots)
above information is generated by processing queries in octave that i felt curious about, based on data taken from "handbook of the birds of the world"
below slideshow gives an idea of family-wise diversity of indian birds