And if you clear the #species recognized by Clements from the species Extinct, Extinct in the Wild or possibly extinct you get this:
Ducks, Geese and Waterfowl 128 / 164 = 78,0%
128 / (164-4 extinct) = 80%
Guans, Chachalacas and Curassows 27 / 54 = 50,0%
27 / (54-1 extinct in the Wild**) = 50,9%
Pheasant, Grouse and Allies 74 / 175 = 42,3%
74 / (175-2 extinct) = 42,8%
16 / (22-3 extinct) = 84,2%
Storm-Petrels 7 / 25 = 28,0%
7/ (25-1 extinct) = 29,2%
Cormorants and Shags 23 / 40 = 57,5%
23 / (40-1 extinct) = 59,0%
Herons, Egrets and Bitterns 50 / 64 = 78,1%
50 / (64- 1 extinct) = 79,4%
Ibises and Spoonbills 24 / 34 = 70,6%
24 / (34-1 extinct) = 72,7%
Rails, Gallinules and Coots 74 / 144 = 51,4%
74 / (144-11 extinct-1 extinct in the wild**- 1 possibly extinct*) = 56,5%
Oystercatchers 10 / 12 = 83,3%
10 / (12-1 extinct) = 90,9%
Plovers and Lapwings 55 / 67 = 82,1%
55 / (67-1 possibly extinct*) = 83,3%
Sandpipers and Allies 64 / 97 = 66,0%
64 / (97-6 extinct-2 possibly extinct*) = 67,4%
Auks, Murres and Puffins 9 / 25 = 36,0%
9 / (25-1 extinct) = 37,5%
Pigeons and Doves 139 / 330 = 42,1%
139 / (330-9 extinct-1 extinct in the wild**- 1 possibly extinct*) = 43,6%
93 / (144-1 extinct) = 64,6%
102 / (207-1 extinct) = 49,5%
Nightjars and Allies 54 / 97 = 55,7%
54 / (97-6 extinct-2 possibly extinct*) = 56,25%
Hummingbirds 217 / 342 = 63,5%
217 / (342-2 extinct) = 63,8%
Kingfishers 59 / 117 = 50,4%
59 / (117-1 extinct-1 extinct in the wild**) = 51,3%
Woodpeckers 162 / 230 = 70,4%
162 / (230-2 possibly extinct*) = 71,1%
Falcons and Caracaras 43 / 66 = 65,2%
43 / (66-1 extinct) = 66,2%
New Zealand Parrots 1 / 4 = 25,0%
1 / (4-1 extinct) = 33,3%
Old World Parrots 70 / 180 = 38,9%
70 / (180-7 extinct) = 40,5%
New Zealand Wrens 1 / 4 = 25,0%
1 / (4-2 extinct) = 50%
Honeyeaters 72 / 184 = 39,1%
72 / (184-1 extinct) = 39,3%
Thornbills and Allies 44 / 64 = 68,8%
44 / (64-1 extinct) = 69,8%
Wattlebirds 2 / 5 = 40,0%
2 / (5-2 extinct) = 66,7%
Old World Orioles 21 / 35 = 60,0%
21 / (35-1 extinct) = 61,8%
Monarch Flycatchers 26 / 100 = 26,0%
26 / (100-4 extinct-1 possibly extinct*) = 27,4%
Crows, Jays and Magpies 81 / 124 = 65,3%
81 / (124-1 extinct in the wild**) = 65,9%
59 / (86- 1 possibly extinct*) = 69,4%
Reed-Warblers and Allies 24 / 61 = 39,3%
24 / (61-4 extinct-3 possibly extinct*) = 44,4%
Grassbirds and Allies 24 / 61 = 39,3%
24 / (61-1 extinct) = 40,0%
Yuhinas, White-eyes and Allies 35 / 129 = 27,1%
35 / (129-2 extinct-1 possibly extinct*) = 27,8%
Ground Babblers and Allies 31 / 56 = 55,4%
31 / (56-1 extinct) = 56,4%
Thrushes and Allies 96 / 166 = 57,8%
96 / (166-3 extinct-2 possibly extinct*) = 59,6%
Starlings 63 / 122 = 51,6%
63 / (122-5 extinct) = 53,9%
Flowerpeckers 27 / 47 = 57,4%
27 / (47-1 possibly extinct*) = 58,7%
New World Warblers 81 / 114 = 71,1%
81 / (114-2 possibly extinct*) = 72,3%
Troupials and Allies 75 / 105 = 71,4%
75 / (105-1 extinct) = 72,1%
Finches, Euphonias and Allies 104 / 224 = 46,4%
104 / (224-17 extinct-7 possibly extinct*) = 52,0%
* Possibly Extinct: New Caledonian Rail, Javan Lapwing, Eskimo Curlew, Slender-billed Curlew, Thick-billed Ground-Dove, Ivory-billed Woodpecker, Imperial Woodpecker, Glaucous Macaw, Ua Pou Monarch, White-eyed River Martin, Aldabra Brush-Warbler, Society Islands Reed-Warbler, Moorea Reed-Warbler, White-chested White-eye, Kamao, Olomao, Bachman's Warbler, Semper's Warbler, Poo-uli, Oahu Alauahio, Ou, Kauai Nukupuu, Maui Nukupuu, Maui Akepa
**Extinct in the Wild: Alagoas Curassow, Guam Rail, Guam Kingfisher, Spix's Macaw, Hawaiian Crow
Furthermore virtually impossible/impossible to count: Campbell Island Teal, Madagascar Pochard, Edward's Pheasant, Nechisar Nightjar, Kakapo, Night Parrot. I'm sure I still missed many...
Maffong