Confused pairs
Incorrect answers between two species (undirected). With a country selected, only mix-ups from games in that country are counted, and only pairs where both species are on that country's checklist are shown.
| Species A (lower id) | Species B (higher id) | Total wrong | A was target → picked B | B was target → picked A |
|---|---|---|---|---|
| Arctic Skua Stercorarius parasiticus | Pomarine Skua Stercorarius pomarinus | 3 | 1 | 2 |
| Rough-legged Buzzard Buteo lagopus | Common Buzzard Buteo buteo | 3 | 3 | 0 |
| House Sparrow Passer domesticus | Italian Sparrow Passer italiae | 3 | 0 | 3 |
| Northern Pintail Anas acuta | Common Pochard Aythya ferina | 2 | 2 | 0 |
| Little Grebe Tachybaptus ruficollis | Great Crested Grebe Podiceps cristatus | 2 | 1 | 1 |
| Stock Dove Columba oenas | Common Woodpigeon Columba palumbus | 2 | 2 | 0 |
| Alpine Swift Tachymarptis melba | Common Swift Apus apus | 2 | 2 | 0 |
| Eurasian Dotterel Eudromias morinellus | Great Snipe Gallinago media | 2 | 2 | 0 |
| Eurasian Curlew Numenius arquata | Great Snipe Gallinago media | 2 | 0 | 2 |
| Marsh Sandpiper Tringa stagnatilis | Pectoral Sandpiper Calidris melanotos | 2 | 1 | 1 |
| Common Sandpiper Actitis hypoleucos | Dunlin Calidris alpina | 2 | 0 | 2 |
| Yellow-legged Gull Larus michahellis | Gull-billed Tern Gelochelidon nilotica | 2 | 0 | 2 |
| Gull-billed Tern Gelochelidon nilotica | Arctic Tern Sterna paradisaea | 2 | 2 | 0 |
| Arctic Tern Sterna paradisaea | Sandwich Tern Thalasseus sandvicensis | 2 | 0 | 2 |
| European Honey-buzzard Pernis apivorus | Short-toed Eagle Circaetus gallicus | 2 | 0 | 2 |
| Great Spotted Woodpecker Dendrocopos major | Eurasian Green Woodpecker Picus viridis | 2 | 0 | 2 |
| Lesser Kestrel Falco naumanni | Common Kestrel Falco tinnunculus | 2 | 2 | 0 |
| Greater Short-toed Lark Calandrella brachydactyla | Eurasian Skylark Alauda arvensis | 2 | 2 | 0 |
| Western Subalpine Warbler Curruca iberiae | Eastern Subalpine Warbler Curruca cantillans | 2 | 1 | 1 |
| Richard's Pipit Anthus richardi | Tawny Pipit Anthus campestris | 2 | 2 | 0 |
| Citril Finch Carduelis citrinella | European Serin Serinus serinus | 2 | 0 | 2 |
| Northern Shoveler Spatula clypeata | Mallard Anas platyrhynchos | 1 | 1 | 0 |
| Northern Shoveler Spatula clypeata | Eurasian Wigeon Mareca penelope | 1 | 0 | 1 |
| Northern Pintail Anas acuta | Red-crested Pochard Netta rufina | 1 | 1 | 0 |
| Eurasian/Green-winged Teal Anas crecca | Red-crested Pochard Netta rufina | 1 | 1 | 0 |
| Tufted Duck Aythya fuligula | Eurasian Goshawk Astur gentilis | 1 | 1 | 0 |
| Red-crested Pochard Netta rufina | Goosander Mergus merganser | 1 | 0 | 1 |
| Common Pochard Aythya ferina | Goosander Mergus merganser | 1 | 0 | 1 |
| Goosander Mergus merganser | Common Moorhen Gallinula chloropus | 1 | 1 | 0 |
| Western Capercaillie Tetrao urogallus | Black Grouse Lyrurus tetrix | 1 | 0 | 1 |
| Rock Partridge Alectoris graeca | White-throated Dipper Cinclus cinclus | 1 | 1 | 0 |
| Black Grouse Lyrurus tetrix | Little Grebe Tachybaptus ruficollis | 1 | 0 | 1 |
| Eurasian Nightjar Caprimulgus europaeus | Pallid Swift Apus pallidus | 1 | 1 | 0 |
| Common Moorhen Gallinula chloropus | Stone-curlew Burhinus oedicnemus | 1 | 1 | 0 |
| Grey Plover Pluvialis squatarola | Yelkouan Shearwater Puffinus yelkouan | 1 | 1 | 0 |
| Common Sandpiper Actitis hypoleucos | Marsh Sandpiper Tringa stagnatilis | 1 | 1 | 0 |
| Broad-billed Sandpiper Calidris falcinellus | Dunlin Calidris alpina | 1 | 1 | 0 |
| Collared Pratincole Glareola pratincola | Long-tailed Skua Stercorarius longicaudus | 1 | 1 | 0 |
| Pectoral Sandpiper Calidris melanotos | Arctic Skua Stercorarius parasiticus | 1 | 0 | 1 |
| Long-tailed Skua Stercorarius longicaudus | Pomarine Skua Stercorarius pomarinus | 1 | 0 | 1 |
| Long-tailed Skua Stercorarius longicaudus | Great Skua Stercorarius skua | 1 | 0 | 1 |
| Sabine's Gull Xema sabini | Black-headed Gull Chroicocephalus ridibundus | 1 | 1 | 0 |
| Black-headed Gull Chroicocephalus ridibundus | Little Tern Sternula albifrons | 1 | 1 | 0 |
| Black-headed Gull Chroicocephalus ridibundus | Mediterranean Gull Ichthyaetus melanocephalus | 1 | 0 | 1 |
| Little Tern Sternula albifrons | Gull-billed Tern Gelochelidon nilotica | 1 | 1 | 0 |
| Black Tern Chlidonias niger | Arctic Tern Sterna paradisaea | 1 | 0 | 1 |
| Arctic Tern Sterna paradisaea | Common Tern Sterna hirundo | 1 | 1 | 0 |
| White-winged Black Tern Chlidonias leucopterus | Common Tern Sterna hirundo | 1 | 0 | 1 |
| Little Gull Hydrocoloeus minutus | Roseate Tern Sterna dougallii | 1 | 0 | 1 |
| Black-throated Diver Gavia arctica | Pacific Diver Gavia pacifica | 1 | 0 | 1 |
| Bearded Vulture Gypaetus barbatus | Egyptian Vulture Neophron percnopterus | 1 | 1 | 0 |
| Bearded Vulture Gypaetus barbatus | European Honey-buzzard Pernis apivorus | 1 | 0 | 1 |
| Greater Spotted Eagle Clanga clanga | Booted Eagle Hieraaetus pennatus | 1 | 1 | 0 |
| Short-toed Eagle Circaetus gallicus | Booted Eagle Hieraaetus pennatus | 1 | 0 | 1 |
| Booted Eagle Hieraaetus pennatus | Golden Eagle Aquila chrysaetos | 1 | 1 | 0 |
| Eurasian Sparrowhawk Accipiter nisus | Red Kite Milvus milvus | 1 | 0 | 1 |
| Red Kite Milvus milvus | Black Kite Milvus migrans | 1 | 1 | 0 |
| Common Buzzard Buteo buteo | Northern Wheatear Oenanthe oenanthe | 1 | 1 | 0 |
| Eurasian Eagle Owl Bubo bubo | Tawny Owl Strix aluco | 1 | 1 | 0 |
| Eurasian Eagle Owl Bubo bubo | Long-eared Owl Asio otus | 1 | 1 | 0 |
| Tawny Owl Strix aluco | Long-eared Owl Asio otus | 1 | 0 | 1 |
| Great Spotted Woodpecker Dendrocopos major | House Sparrow Passer domesticus | 1 | 1 | 0 |
| Common Kestrel Falco tinnunculus | Peregrine Falcon Falco peregrinus | 1 | 1 | 0 |
| Red-backed Shrike Lanius collurio | Isabelline Shrike Lanius isabellinus | 1 | 0 | 1 |
| Long-tailed Shrike Lanius schach | Eurasian Bullfinch Pyrrhula pyrrhula | 1 | 1 | 0 |
| Spotted Nutcracker Nucifraga caryocatactes | White-winged Snowfinch Montifringilla nivalis | 1 | 1 | 0 |
| Spotted Nutcracker Nucifraga caryocatactes | Red-billed Chough Pyrrhocorax pyrrhocorax | 1 | 0 | 1 |
| Alpine Chough Pyrrhocorax graculus | Eurasian Blackbird Turdus merula | 1 | 1 | 0 |
| Carrion Crow Corvus corone | Common Raven Corvus corax | 1 | 0 | 1 |
| Shore Lark Eremophila alpestris | Water Pipit Anthus spinoletta | 1 | 1 | 0 |
| Woodlark Lullula arborea | Eurasian Skylark Alauda arvensis | 1 | 1 | 0 |
| Woodlark Lullula arborea | Crested Lark Galerida cristata | 1 | 1 | 0 |
| Crested Lark Galerida cristata | Aquatic Warbler Acrocephalus paludicola | 1 | 0 | 1 |
| Aquatic Warbler Acrocephalus paludicola | Great Reed Warbler Acrocephalus arundinaceus | 1 | 1 | 0 |
| Moustached Warbler Acrocephalus melanopogon | Paddyfield Warbler Acrocephalus agricola | 1 | 1 | 0 |
| Booted Warbler Iduna caligata | Blyth's Reed Warbler Acrocephalus dumetorum | 1 | 0 | 1 |
| Sedge Warbler Acrocephalus schoenobaenus | Marsh Warbler Acrocephalus palustris | 1 | 0 | 1 |
| Marsh Warbler Acrocephalus palustris | River Warbler Locustella fluviatilis | 1 | 1 | 0 |
| Eurasian Crag Martin Ptyonoprogne rupestris | Western House Martin Delichon urbicum | 1 | 1 | 0 |
| Eurasian Crag Martin Ptyonoprogne rupestris | Red-rumped Swallow Cecropis daurica | 1 | 1 | 0 |
| Barn Swallow Hirundo rustica | Red-rumped Swallow Cecropis daurica | 1 | 0 | 1 |
| Western House Martin Delichon urbicum | Red-rumped Swallow Cecropis daurica | 1 | 0 | 1 |
| Wood Warbler Phylloscopus sibilatrix | Western Bonelli's Warbler Phylloscopus bonelli | 1 | 0 | 1 |
| Willow Warbler Phylloscopus trochilus | Common Chiffchaff Phylloscopus collybita | 1 | 1 | 0 |
| Western Bonelli's Warbler Phylloscopus bonelli | Common Chiffchaff Phylloscopus collybita | 1 | 0 | 1 |
| Common Chiffchaff Phylloscopus collybita | Greenish Warbler Phylloscopus trochiloides | 1 | 0 | 1 |
| Eurasian Blackcap Sylvia atricapilla | Fieldfare Turdus pilaris | 1 | 1 | 0 |
| Eurasian Blackcap Sylvia atricapilla | European Robin Erithacus rubecula | 1 | 1 | 0 |
| Common Whitethroat Curruca communis | Goldcrest Regulus regulus | 1 | 0 | 1 |
| Goldcrest Regulus regulus | Common Firecrest Regulus ignicapilla | 1 | 1 | 0 |
| Eurasian Treecreeper Certhia familiaris | White-throated Dipper Cinclus cinclus | 1 | 1 | 0 |
| Common Starling Sturnus vulgaris | Eurasian Blackbird Turdus merula | 1 | 1 | 0 |
| Common Starling Sturnus vulgaris | Eurasian Siskin Spinus spinus | 1 | 1 | 0 |
| Mistle Thrush Turdus viscivorus | Song Thrush Turdus philomelos | 1 | 0 | 1 |
| Mistle Thrush Turdus viscivorus | Eurasian Blackbird Turdus merula | 1 | 0 | 1 |
| Little Tern Sternula albifrons | Fieldfare Turdus pilaris | 1 | 0 | 1 |
| Ring Ouzel Turdus torquatus | Thrush Nightingale Luscinia luscinia | 1 | 1 | 0 |
| European Pied Flycatcher Ficedula hypoleuca | Black Redstart Phoenicurus ochruros | 1 | 0 | 1 |
| Black Redstart Phoenicurus ochruros | Eurasian Siskin Spinus spinus | 1 | 1 | 0 |
| Common Rock Thrush Monticola saxatilis | Northern Wheatear Oenanthe oenanthe | 1 | 1 | 0 |
| Common Rock Thrush Monticola saxatilis | European Stonechat Saxicola rubicola | 1 | 0 | 1 |
| European Stonechat Saxicola rubicola | Northern Wheatear Oenanthe oenanthe | 1 | 1 | 0 |
| Black-necked Grebe Podiceps nigricollis | Western Black-eared Wheatear Oenanthe hispanica | 1 | 0 | 1 |
| Pacific Golden Plover Pluvialis fulva | Eastern Black-eared Wheatear Oenanthe melanoleuca | 1 | 0 | 1 |
| Dunnock Prunella modularis | Eurasian Tree Sparrow Passer montanus | 1 | 1 | 0 |
| House Sparrow Passer domesticus | Spanish Sparrow Passer hispaniolensis | 1 | 0 | 1 |
| Spanish Sparrow Passer hispaniolensis | Eurasian Tree Sparrow Passer montanus | 1 | 1 | 0 |
| Pied Avocet Recurvirostra avosetta | Grey Wagtail Motacilla cinerea | 1 | 0 | 1 |
| Tawny Pipit Anthus campestris | Tree Pipit Anthus trivialis | 1 | 1 | 0 |
| Fieldfare Turdus pilaris | Tree Pipit Anthus trivialis | 1 | 0 | 1 |
| Tree Pipit Anthus trivialis | Olive-backed Pipit Anthus hodgsoni | 1 | 0 | 1 |
| Eurasian Skylark Alauda arvensis | Water Pipit Anthus spinoletta | 1 | 0 | 1 |
| Spotted Nutcracker Nucifraga caryocatactes | Common Chaffinch Fringilla coelebs | 1 | 0 | 1 |
| Common Starling Sturnus vulgaris | Common Chaffinch Fringilla coelebs | 1 | 0 | 1 |
| Hawfinch Coccothraustes coccothraustes | European Greenfinch Chloris chloris | 1 | 0 | 1 |
| Spotted Nutcracker Nucifraga caryocatactes | Eurasian Siskin Spinus spinus | 1 | 0 | 1 |
| Thrush Nightingale Luscinia luscinia | Eurasian Siskin Spinus spinus | 1 | 0 | 1 |
| Northern Wheatear Oenanthe oenanthe | Lapland Bunting Calcarius lapponicus | 1 | 0 | 1 |
| Common Rock Thrush Monticola saxatilis | Common Reed Bunting Emberiza schoeniclus | 1 | 0 | 1 |
| Little Bunting Emberiza pusilla | Rustic Bunting Emberiza rustica | 1 | 1 | 0 |