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 |
|---|---|---|---|---|
| Gadwall Mareca strepera | Northern Pintail Anas acuta | 2 | 2 | 0 |
| Tufted Duck Aythya fuligula | Greater Scaup Aythya marila | 2 | 0 | 2 |
| Great Black-backed Gull Larus marinus | Lesser Black-backed Gull Larus fuscus | 2 | 1 | 1 |
| Gadwall Mareca strepera | Eurasian Wigeon Mareca penelope | 1 | 0 | 1 |
| Ring-necked Duck Aythya collaris | Black-headed Bunting Emberiza melanocephala | 1 | 1 | 0 |
| Bar-tailed Godwit Limosa lapponica | Black-tailed Godwit Limosa limosa | 1 | 1 | 0 |
| Hudsonian Godwit Limosa haemastica | Long-toed Stint Calidris subminuta | 1 | 1 | 0 |
| Eurasian Woodcock Scolopax rusticola | Common Snipe Gallinago gallinago | 1 | 1 | 0 |
| Common Sandpiper Actitis hypoleucos | Common Greenshank Tringa nebularia | 1 | 1 | 0 |
| Common Snipe Gallinago gallinago | Common Redshank Tringa totanus | 1 | 0 | 1 |
| Ruddy Turnstone Arenaria interpres | Black Kite Milvus migrans | 1 | 1 | 0 |
| Red Knot Calidris canutus | Dunlin Calidris alpina | 1 | 1 | 0 |
| Sanderling Calidris alba | Purple Sandpiper Calidris maritima | 1 | 0 | 1 |
| Arctic Skua Stercorarius parasiticus | Great Skua Stercorarius skua | 1 | 1 | 0 |
| Atlantic Puffin Fratercula arctica | Razorbill Alca torda | 1 | 1 | 0 |
| Black Guillemot Cepphus grylle | Common Guillemot Uria aalge | 1 | 0 | 1 |
| Razorbill Alca torda | Common Guillemot Uria aalge | 1 | 0 | 1 |
| Common Gull Larus canus | Lesser Black-backed Gull Larus fuscus | 1 | 1 | 0 |
| Black-headed Gull Chroicocephalus ridibundus | Herring Gull Larus argentatus | 1 | 0 | 1 |
| Arctic Tern Sterna paradisaea | Common Tern Sterna hirundo | 1 | 0 | 1 |
| Red-throated Diver Gavia stellata | Great Northern Diver Gavia immer | 1 | 0 | 1 |
| European Storm-Petrel Hydrobates pelagicus | Leach's Storm-Petrel Hydrobates leucorhous | 1 | 1 | 0 |
| Black-legged Kittiwake Rissa tridactyla | Leach's Storm-Petrel Hydrobates leucorhous | 1 | 0 | 1 |
| Great Shearwater Ardenna gravis | Sooty Shearwater Ardenna grisea | 1 | 1 | 0 |
| Hen Harrier Circus cyaneus | Black Kite Milvus migrans | 1 | 1 | 0 |
| Carrion Crow Corvus corone | Common Raven Corvus corax | 1 | 1 | 0 |
| Redwing Turdus iliacus | Fieldfare Turdus pilaris | 1 | 0 | 1 |
| Pallas's Warbler Phylloscopus proregulus | Western Black-eared Wheatear Oenanthe hispanica | 1 | 0 | 1 |
| House Sparrow Passer domesticus | Eurasian Tree Sparrow Passer montanus | 1 | 1 | 0 |
| Eurasian Goshawk Astur gentilis | Meadow Pipit Anthus pratensis | 1 | 0 | 1 |
| Common Linnet Linaria cannabina | Common Redpoll Acanthis flammea | 1 | 0 | 1 |
| Common Redpoll Acanthis flammea | Lesser Redpoll Acanthis cabaret | 1 | 0 | 1 |
| Bearded Tit Panurus biarmicus | Snow Bunting Plectrophenax nivalis | 1 | 0 | 1 |