Jon Clark: World Year List 2021 IOC, All records: Top Blockers Record(s) 1 to 198 of 198 total.
Seq.	Species	Scientific Name	Seen By Other Listers	Other Listers (%)	
1	Brent Goose	Branta bernicla	8	53.33	
2	Red-breasted Goose	Branta ruficollis	3	20.00	
3	Canada Goose	Branta canadensis	12	80.00	
4	Barnacle Goose	Branta leucopsis	4	26.67	
5	Greylag Goose	Anser anser	10	66.67	
6	Pink-footed Goose	Anser brachyrhynchus	4	26.67	
7	Greater White-fronted Goose	Anser albifrons	10	66.67	
8	Mute Swan	Cygnus olor	11	73.33	
9	Tundra Swan	Cygnus columbianus	7	46.67	
10	Egyptian Goose	Alopochen aegyptiaca	10	66.67	
11	Common Shelduck	Tadorna tadorna	9	60.00	
12	Garganey	Spatula querquedula	6	40.00	
13	Northern Shoveler	Spatula clypeata	12	80.00	
14	Gadwall	Mareca strepera	11	73.33	
15	Eurasian Wigeon	Mareca penelope	11	73.33	
16	Mallard	Anas platyrhynchos	12	80.00	
17	Northern Pintail	Anas acuta	11	73.33	
18	Eurasian Teal	Anas crecca	11	73.33	
19	Common Pochard	Aythya ferina	8	53.33	
20	Tufted Duck	Aythya fuligula	10	66.67	
21	Greater Scaup	Aythya marila	8	53.33	
22	Common Eider	Somateria mollissima	8	53.33	
23	Long-tailed Duck	Clangula hyemalis	5	33.33	
24	Common Goldeneye	Bucephala clangula	8	53.33	
25	Smew	Mergellus albellus	3	20.00	
26	Common Merganser	Mergus merganser	11	73.33	
27	Red-breasted Merganser	Mergus serrator	10	66.67	
28	Common Pheasant	Phasianus colchicus	10	66.67	
29	Red-legged Partridge	Alectoris rufa	8	53.33	
30	European Nightjar	Caprimulgus europaeus	5	33.33	
31	Common Swift	Apus apus	9	60.00	
32	Common Cuckoo	Cuculus canorus	7	46.67	
33	Rock Dove	Columba livia	11	73.33	
34	Stock Dove	Columba oenas	8	53.33	
35	Common Wood Pigeon	Columba palumbus	10	66.67	
36	European Turtle Dove	Streptopelia turtur	5	33.33	
37	Eurasian Collared Dove	Streptopelia decaocto	10	66.67	
38	Water Rail	Rallus aquaticus	6	40.00	
39	Common Moorhen	Gallinula chloropus	9	60.00	
40	Eurasian Coot	Fulica atra	10	66.67	
41	Little Grebe	Tachybaptus ruficollis	10	66.67	
42	Red-necked Grebe	Podiceps grisegena	6	40.00	
43	Great Crested Grebe	Podiceps cristatus	10	66.67	
44	Horned Grebe	Podiceps auritus	6	40.00	
45	Black-necked Grebe	Podiceps nigricollis	9	60.00	
46	Eurasian Oystercatcher	Haematopus ostralegus	10	66.67	
47	Pied Avocet	Recurvirostra avosetta	10	66.67	
48	Grey Plover	Pluvialis squatarola	11	73.33	
49	European Golden Plover	Pluvialis apricaria	8	53.33	
50	Common Ringed Plover	Charadrius hiaticula	10	66.67	
51	Little Ringed Plover	Charadrius dubius	7	46.67	
52	Northern Lapwing	Vanellus vanellus	11	73.33	
53	White-tailed Lapwing	Vanellus leucurus	2	13.33	
54	Eurasian Whimbrel	Numenius phaeopus	6	40.00	
55	Eurasian Curlew	Numenius arquata	10	66.67	
56	Bar-tailed Godwit	Limosa lapponica	8	53.33	
57	Black-tailed Godwit	Limosa limosa	9	60.00	
58	Common Snipe	Gallinago gallinago	8	53.33	
59	Common Sandpiper	Actitis hypoleucos	8	53.33	
60	Green Sandpiper	Tringa ochropus	9	60.00	
61	Wood Sandpiper	Tringa glareola	8	53.33	
62	Common Redshank	Tringa totanus	10	66.67	
63	Spotted Redshank	Tringa erythropus	7	46.67	
64	Common Greenshank	Tringa nebularia	9	60.00	
65	Ruddy Turnstone	Arenaria interpres	11	73.33	
66	Red Knot	Calidris canutus	7	46.67	
67	Ruff	Calidris pugnax	9	60.00	
68	Curlew Sandpiper	Calidris ferruginea	8	53.33	
69	Buff-breasted Sandpiper	Calidris subruficollis	2	13.33	
70	Sanderling	Calidris alba	8	53.33	
71	Dunlin	Calidris alpina	12	80.00	
72	Purple Sandpiper	Calidris maritima	5	33.33	
73	Little Stint	Calidris minuta	7	46.67	
74	Little Tern	Sternula albifrons	4	26.67	
75	Black Tern	Chlidonias niger	7	46.67	
76	Arctic Tern	Sterna paradisaea	4	26.67	
77	Common Tern	Sterna hirundo	7	46.67	
78	Sandwich Tern	Thalasseus sandvicensis	7	46.67	
79	Little Gull	Hydrocoloeus minutus	4	26.67	
80	Black-legged Kittiwake	Rissa tridactyla	5	33.33	
81	Black-headed Gull	Chroicocephalus ridibundus	11	73.33	
82	Mediterranean Gull	Ichthyaetus melanocephalus	6	40.00	
83	Common Gull	Larus canus	8	53.33	
84	European Herring Gull	Larus argentatus	10	66.67	
85	Great Black-backed Gull	Larus marinus	10	66.67	
86	Lesser Black-backed Gull	Larus fuscus	11	73.33	
87	Great Skua	Stercorarius skua	4	26.67	
88	Atlantic Puffin	Fratercula arctica	2	13.33	
89	Black Guillemot	Cepphus grylle	3	20.00	
90	Razorbill	Alca torda	5	33.33	
91	Common Murre	Uria aalge	7	46.67	
92	Red-throated Diver	Gavia stellata	7	46.67	
93	Great Northern Diver	Gavia immer	9	60.00	
94	Black-browed Albatross	Thalassarche melanophris	2	13.33	
95	Northern Fulmar	Fulmarus glacialis	6	40.00	
96	Manx Shearwater	Puffinus puffinus	4	26.67	
97	Northern Gannet	Morus bassanus	7	46.67	
98	Great Cormorant	Phalacrocorax carbo	11	73.33	
99	European Shag	Gulosus aristotelis	7	46.67	
100	Eurasian Spoonbill	Platalea leucorodia	7	46.67	
101	Eurasian Bittern	Botaurus stellaris	5	33.33	
102	Little Egret	Egretta garzetta	11	73.33	
103	Western Cattle Egret	Bubulcus ibis	9	60.00	
104	Great Egret	Ardea alba	11	73.33	
105	Grey Heron	Ardea cinerea	11	73.33	
106	Golden Eagle	Aquila chrysaetos	5	33.33	
107	Eurasian Sparrowhawk	Accipiter nisus	9	60.00	
108	Western Marsh Harrier	Circus aeruginosus	9	60.00	
109	Hen Harrier	Circus cyaneus	5	33.33	
110	Red Kite	Milvus milvus	10	66.67	
111	White-tailed Eagle	Haliaeetus albicilla	4	26.67	
112	Common Buzzard	Buteo buteo	12	80.00	
113	Western Barn Owl	Tyto alba	6	40.00	
114	Short-eared Owl	Asio flammeus	7	46.67	
115	Tawny Owl	Strix aluco	7	46.67	
116	Common Kingfisher	Alcedo atthis	8	53.33	
117	Great Spotted Woodpecker	Dendrocopos major	10	66.67	
118	European Green Woodpecker	Picus viridis	10	66.67	
119	Common Kestrel	Falco tinnunculus	12	80.00	
120	Red-footed Falcon	Falco vespertinus	4	26.67	
121	Merlin	Falco columbarius	8	53.33	
122	Eurasian Hobby	Falco subbuteo	5	33.33	
123	Peregrine Falcon	Falco peregrinus	10	66.67	
124	Rose-ringed Parakeet	Psittacula krameri	5	33.33	
125	Woodchat Shrike	Lanius senator	4	26.67	
126	Eurasian Jay	Garrulus glandarius	10	66.67	
127	Eurasian Magpie	Pica pica	12	80.00	
128	Red-billed Chough	Pyrrhocorax pyrrhocorax	4	26.67	
129	Western Jackdaw	Coloeus monedula	9	60.00	
130	Rook	Corvus frugilegus	9	60.00	
131	Carrion Crow	Corvus corone	11	73.33	
132	Hooded Crow	Corvus cornix	6	40.00	
133	Northern Raven	Corvus corax	11	73.33	
134	Coal Tit	Periparus ater	10	66.67	
135	Marsh Tit	Poecile palustris	6	40.00	
136	Eurasian Blue Tit	Cyanistes caeruleus	11	73.33	
137	Great Tit	Parus major	11	73.33	
138	Bearded Reedling	Panurus biarmicus	5	33.33	
139	Woodlark	Lullula arborea	3	20.00	
140	Eurasian Skylark	Alauda arvensis	9	60.00	
141	Sand Martin	Riparia riparia	10	66.67	
142	Barn Swallow	Hirundo rustica	12	80.00	
143	Western House Martin	Delichon urbicum	7	46.67	
144	Cetti's Warbler	Cettia cetti	6	40.00	
145	Long-tailed Tit	Aegithalos caudatus	11	73.33	
146	Willow Warbler	Phylloscopus trochilus	8	53.33	
147	Common Chiffchaff	Phylloscopus collybita	10	66.67	
148	Sedge Warbler	Acrocephalus schoenobaenus	8	53.33	
149	Common Reed Warbler	Acrocephalus scirpaceus	7	46.67	
150	Common Grasshopper Warbler	Locustella naevia	5	33.33	
151	Eurasian Blackcap	Sylvia atricapilla	9	60.00	
152	Garden Warbler	Sylvia borin	7	46.67	
153	Barred Warbler	Curruca nisoria	2	13.33	
154	Lesser Whitethroat	Curruca curruca	5	33.33	
155	Common Whitethroat	Curruca communis	6	40.00	
156	Dartford Warbler	Curruca undata	4	26.67	
157	Common Firecrest	Regulus ignicapilla	7	46.67	
158	Goldcrest	Regulus regulus	8	53.33	
159	Eurasian Wren	Troglodytes troglodytes	9	60.00	
160	Eurasian Nuthatch	Sitta europaea	10	66.67	
161	Eurasian Treecreeper	Certhia familiaris	9	60.00	
162	Common Starling	Sturnus vulgaris	12	80.00	
163	Song Thrush	Turdus philomelos	10	66.67	
164	Mistle Thrush	Turdus viscivorus	9	60.00	
165	Redwing	Turdus iliacus	10	66.67	
166	Common Blackbird	Turdus merula	11	73.33	
167	Fieldfare	Turdus pilaris	9	60.00	
168	Ring Ouzel	Turdus torquatus	5	33.33	
169	Spotted Flycatcher	Muscicapa striata	6	40.00	
170	European Robin	Erithacus rubecula	11	73.33	
171	Common Nightingale	Luscinia megarhynchos	5	33.33	
172	Common Redstart	Phoenicurus phoenicurus	7	46.67	
173	Whinchat	Saxicola rubetra	6	40.00	
174	European Stonechat	Saxicola rubicola	10	66.67	
175	Northern Wheatear	Oenanthe oenanthe	6	40.00	
176	White-throated Dipper	Cinclus cinclus	7	46.67	
177	Eurasian Tree Sparrow	Passer montanus	7	46.67	
178	House Sparrow	Passer domesticus	14	93.33	
179	Dunnock	Prunella modularis	11	73.33	
180	Western Yellow Wagtail	Motacilla flava	7	46.67	
181	Grey Wagtail	Motacilla cinerea	10	66.67	
182	White Wagtail	Motacilla alba	10	66.67	
183	Meadow Pipit	Anthus pratensis	9	60.00	
184	Tree Pipit	Anthus trivialis	6	40.00	
185	European Rock Pipit	Anthus petrosus	7	46.67	
186	Eurasian Chaffinch	Fringilla coelebs	6	40.00	
187	Eurasian Bullfinch	Pyrrhula pyrrhula	10	66.67	
188	European Greenfinch	Chloris chloris	10	66.67	
189	Twite	Linaria flavirostris	2	13.33	
190	Common Linnet	Linaria cannabina	8	53.33	
191	Lesser Redpoll	Acanthis cabaret	5	33.33	
192	European Goldfinch	Carduelis carduelis	11	73.33	
193	Eurasian Siskin	Spinus spinus	9	60.00	
194	Snow Bunting	Plectrophenax nivalis	6	40.00	
195	Corn Bunting	Emberiza calandra	6	40.00	
196	Yellowhammer	Emberiza citrinella	7	46.67	
197	Cirl Bunting	Emberiza cirlus	6	40.00	
198	Common Reed Bunting	Emberiza schoeniclus	9	60.00