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 |
|---|---|---|---|---|
| Trumpeter Swan Cygnus buccinator | Bewick's Swan Cygnus columbianus | 5 | 3 | 2 |
| Slavonian Grebe Podiceps auritus | Black-necked Grebe Podiceps nigricollis | 4 | 0 | 4 |
| Gadwall Mareca strepera | American Wigeon Mareca americana | 4 | 2 | 2 |
| Greater Scaup Aythya marila | Lesser Scaup Aythya affinis | 4 | 2 | 2 |
| Surf Scoter Melanitta perspicillata | Black Scoter Melanitta americana | 3 | 2 | 1 |
| King Eider Somateria spectabilis | Common Eider Somateria mollissima | 3 | 0 | 3 |
| Common Goldeneye Bucephala clangula | Barrow's Goldeneye Bucephala islandica | 2 | 0 | 2 |
| Slavonian Grebe Podiceps auritus | Western Grebe Aechmophorus occidentalis | 2 | 1 | 1 |
| Common Goldeneye Bucephala clangula | Hooded Merganser Lophodytes cucullatus | 2 | 1 | 1 |
| Snow Goose Anser caerulescens | Ross's Goose Anser rossii | 2 | 1 | 1 |
| Barrow's Goldeneye Bucephala islandica | Hooded Merganser Lophodytes cucullatus | 2 | 0 | 2 |
| Ringed Teal Callonetta leucophrys | Maned Duck Chenonetta jubata | 2 | 2 | 0 |
| Clapper Rail Rallus crepitans | Sora Porzana carolina | 2 | 0 | 2 |
| Surf Scoter Melanitta perspicillata | White-winged Scoter Melanitta deglandi | 2 | 0 | 2 |
| Hooded Merganser Lophodytes cucullatus | Red-breasted Merganser Mergus serrator | 2 | 0 | 2 |
| Pectoral Sandpiper Calidris melanotos | Semipalmated Sandpiper Calidris pusilla | 2 | 1 | 1 |
| White-throated Sparrow Zonotrichia albicollis | Vesper Sparrow Pooecetes gramineus | 2 | 0 | 2 |
| Bewick's Swan Cygnus columbianus | Whooper Swan Cygnus cygnus | 2 | 1 | 1 |
| Sooty Tern Onychoprion fuscatus | Bridled Tern Onychoprion anaethetus | 2 | 1 | 1 |
| Spotted Sandpiper Actitis macularius | Solitary Sandpiper Tringa solitaria | 2 | 1 | 1 |
| Bufflehead Bucephala albeola | Barrow's Goldeneye Bucephala islandica | 2 | 1 | 1 |
| Ring-necked Duck Aythya collaris | Northern Flicker Colaptes auratus | 1 | 0 | 1 |
| Greater Scaup Aythya marila | King Eider Somateria spectabilis | 1 | 0 | 1 |
| Greater Scaup Aythya marila | Red-breasted Merganser Mergus serrator | 1 | 0 | 1 |
| Common Eider Somateria mollissima | Surf Scoter Melanitta perspicillata | 1 | 0 | 1 |
| Common Eider Somateria mollissima | White-winged Scoter Melanitta deglandi | 1 | 1 | 0 |
| White-winged Scoter Melanitta deglandi | Black Scoter Melanitta americana | 1 | 0 | 1 |
| Black Scoter Melanitta americana | Bufflehead Bucephala albeola | 1 | 1 | 0 |
| Long-tailed Duck Clangula hyemalis | Bufflehead Bucephala albeola | 1 | 1 | 0 |
| Bufflehead Bucephala albeola | Common Goldeneye Bucephala clangula | 1 | 0 | 1 |
| Common Goldeneye Bucephala clangula | Goosander Mergus merganser | 1 | 1 | 0 |
| Common Goldeneye Bucephala clangula | Ruddy Duck Oxyura jamaicensis | 1 | 0 | 1 |
| Barrow's Goldeneye Bucephala islandica | Black-crowned Night Heron Nycticorax nycticorax | 1 | 1 | 0 |
| Hooded Merganser Lophodytes cucullatus | Goosander Mergus merganser | 1 | 0 | 1 |
| Helmeted Guineafowl Numida meleagris | Wild Turkey Meleagris gallopavo | 1 | 1 | 0 |
| Northern Bobwhite Colinus virginianus | Willow Ptarmigan Lagopus lagopus | 1 | 0 | 1 |
| Northern Bobwhite Colinus virginianus | Tufted Titmouse Baeolophus bicolor | 1 | 0 | 1 |
| Ruffed Grouse Bonasa umbellus | Red-legged Partridge Alectoris rufa | 1 | 1 | 0 |
| Willow Ptarmigan Lagopus lagopus | Red-legged Partridge Alectoris rufa | 1 | 1 | 0 |
| Pied-billed Grebe Podilymbus podiceps | Western Grebe Aechmophorus occidentalis | 1 | 1 | 0 |
| Pied-billed Grebe Podilymbus podiceps | Black-headed Grosbeak Pheucticus melanocephalus | 1 | 1 | 0 |
| Slavonian Grebe Podiceps auritus | Ancient Murrelet Synthliboramphus antiquus | 1 | 1 | 0 |
| Band-tailed Pigeon Patagioenas fasciata | Sandwich Tern Thalasseus sandvicensis | 1 | 1 | 0 |
| Passenger Pigeon Ectopistes migratorius | Eastern Kingbird Tyrannus tyrannus | 1 | 1 | 0 |
| Chuck-will's-widow Antrostomus carolinensis | Eastern Whip-poor-will Antrostomus vociferus | 1 | 0 | 1 |
| Rufous Hummingbird Selasphorus rufus | Allen's Hummingbird Selasphorus sasin | 1 | 1 | 0 |
| American Moorhen Gallinula galeata | American Coot Fulica americana | 1 | 1 | 0 |
| Grey Plover Pluvialis squatarola | Pacific Golden Plover Pluvialis fulva | 1 | 0 | 1 |
| Semipalmated Plover Charadrius semipalmatus | Wilson's Plover Anarhynchus wilsonia | 1 | 0 | 1 |
| Upland Sandpiper Bartramia longicauda | Marbled Godwit Limosa fedoa | 1 | 1 | 0 |
| Hudsonian Godwit Limosa haemastica | Long-billed Dowitcher Limnodromus scolopaceus | 1 | 1 | 0 |
| Wilson's Snipe Gallinago delicata | Wilson's Phalarope Phalaropus tricolor | 1 | 1 | 0 |
| Red-necked Phalarope Phalaropus lobatus | Solitary Sandpiper Tringa solitaria | 1 | 1 | 0 |
| Lesser Yellowlegs Tringa flavipes | Greater Yellowlegs Tringa melanoleuca | 1 | 0 | 1 |
| Willet Tringa semipalmata | Red Knot Calidris canutus | 1 | 1 | 0 |
| Surfbird Calidris virgata | Forster's Tern Sterna forsteri | 1 | 1 | 0 |
| Stilt Sandpiper Calidris himantopus | Sanderling Calidris alba | 1 | 1 | 0 |
| Sanderling Calidris alba | Purple Sandpiper Calidris maritima | 1 | 1 | 0 |
| Purple Sandpiper Calidris maritima | Semipalmated Sandpiper Calidris pusilla | 1 | 1 | 0 |
| Baird's Sandpiper Calidris bairdii | White-rumped Sandpiper Calidris fuscicollis | 1 | 1 | 0 |
| Baird's Sandpiper Calidris bairdii | Least Sandpiper Calidris minutilla | 1 | 1 | 0 |
| White-rumped Sandpiper Calidris fuscicollis | House Finch Haemorhous mexicanus | 1 | 1 | 0 |
| Least Sandpiper Calidris minutilla | Pectoral Sandpiper Calidris melanotos | 1 | 0 | 1 |
| Least Sandpiper Calidris minutilla | Western Sandpiper Calidris mauri | 1 | 1 | 0 |
| Long-tailed Skua Stercorarius longicaudus | Arctic Skua Stercorarius parasiticus | 1 | 0 | 1 |
| Black Guillemot Cepphus grylle | Ancient Murrelet Synthliboramphus antiquus | 1 | 1 | 0 |
| Black-legged Kittiwake Rissa tridactyla | Sabine's Gull Xema sabini | 1 | 0 | 1 |
| Kelp Gull Larus dominicanus | Great Black-backed Gull Larus marinus | 1 | 1 | 0 |
| Great Black-backed Gull Larus marinus | Glaucous-winged Gull Larus glaucescens | 1 | 1 | 0 |
| Black Skimmer Rynchops niger | Sooty Tern Onychoprion fuscatus | 1 | 0 | 1 |
| Sooty Tern Onychoprion fuscatus | Least Tern Sternula antillarum | 1 | 1 | 0 |
| Sooty Tern Onychoprion fuscatus | Band-rumped Storm-Petrel Hydrobates castro | 1 | 0 | 1 |
| Gull-billed Tern Gelochelidon nilotica | Caspian Tern Hydroprogne caspia | 1 | 1 | 0 |
| Caspian Tern Hydroprogne caspia | Black Tern Chlidonias niger | 1 | 0 | 1 |
| Black Tern Chlidonias niger | White-winged Black Tern Chlidonias leucopterus | 1 | 0 | 1 |
| Common Tern Sterna hirundo | Royal Tern Thalasseus maximus | 1 | 0 | 1 |
| White-tailed Tropicbird Phaethon lepturus | Great Northern Diver Gavia immer | 1 | 1 | 0 |
| Red-throated Diver Gavia stellata | Townsend's Solitaire Myadestes townsendi | 1 | 1 | 0 |
| Wilson's Storm-Petrel Oceanites oceanicus | Leach's Storm-Petrel Hydrobates leucorhous | 1 | 0 | 1 |
| Wilson's Storm-Petrel Oceanites oceanicus | Band-rumped Storm-Petrel Hydrobates castro | 1 | 0 | 1 |
| Leach's Storm-Petrel Hydrobates leucorhous | Band-rumped Storm-Petrel Hydrobates castro | 1 | 0 | 1 |
| Trindade Petrel Pterodroma arminjoniana | Great Shearwater Ardenna gravis | 1 | 1 | 0 |
| Black-capped Petrel Pterodroma hasitata | Great Shearwater Ardenna gravis | 1 | 1 | 0 |
| Wood Stork Mycteria americana | Brown Booby Sula leucogaster | 1 | 1 | 0 |
| Magnificent Frigatebird Fregata magnificens | Northern Gannet Morus bassanus | 1 | 0 | 1 |
| Northern Gannet Morus bassanus | Brown Booby Sula leucogaster | 1 | 0 | 1 |
| Great Cormorant Phalacrocorax carbo | Double-crested Cormorant Nannopterum auritum | 1 | 1 | 0 |
| Little Blue Heron Egretta caerulea | Tricoloured Heron Egretta tricolor | 1 | 1 | 0 |
| Snowy Egret Egretta thula | Western Cattle-Egret Ardea ibis | 1 | 0 | 1 |
| Green Heron Butorides virescens | Great Blue Heron Ardea herodias | 1 | 0 | 1 |
| Western Cattle-Egret Ardea ibis | Great White Egret Ardea alba | 1 | 1 | 0 |
| White Ibis Eudocimus albus | Glossy Ibis Plegadis falcinellus | 1 | 0 | 1 |
| Mississippi Kite Ictinia mississippiensis | Sharp-shinned Hawk Accipiter striatus | 1 | 1 | 0 |
| Harris's Hawk Parabuteo unicinctus | Red-shouldered Hawk Buteo lineatus | 1 | 1 | 0 |
| Rough-legged Buzzard Buteo lagopus | Ferruginous Hawk Buteo regalis | 1 | 1 | 0 |
| Great Horned Owl Bubo virginianus | Short-eared Owl Asio flammeus | 1 | 0 | 1 |
| Yellow-bellied Sapsucker Sphyrapicus varius | Hairy Woodpecker Leuconotopicus villosus | 1 | 1 | 0 |
| Downy Woodpecker Dryobates pubescens | Hairy Woodpecker Leuconotopicus villosus | 1 | 0 | 1 |
| Acadian Flycatcher Empidonax virescens | Least Flycatcher Empidonax minimus | 1 | 1 | 0 |
| Alder Flycatcher Empidonax alnorum | Willow Flycatcher Empidonax traillii | 1 | 0 | 1 |
| Alder Flycatcher Empidonax alnorum | Least Flycatcher Empidonax minimus | 1 | 1 | 0 |
| Grey Flycatcher Empidonax wrightii | Green-tailed Towhee Pipilo chlorurus | 1 | 0 | 1 |
| Yellow-throated Vireo Vireo flavifrons | Philadelphia Vireo Vireo philadelphicus | 1 | 0 | 1 |
| Yellow-throated Vireo Vireo flavifrons | Seaside Sparrow Ammospiza maritima | 1 | 0 | 1 |
| American Crow Corvus brachyrhynchos | Common Raven Corvus corax | 1 | 0 | 1 |
| Northern Rough-winged Swallow Stelgidopteryx serripennis | Cave Swallow Petrochelidon fulva | 1 | 0 | 1 |
| Barn Swallow Hirundo rustica | Cliff Swallow Petrochelidon pyrrhonota | 1 | 0 | 1 |
| Sedge Wren Cistothorus stellaris | Marsh Wren Cistothorus palustris | 1 | 1 | 0 |
| Marsh Wren Cistothorus palustris | Bewick's Wren Thryomanes bewickii | 1 | 0 | 1 |
| Grey Catbird Dumetella carolinensis | Northern Mockingbird Mimus polyglottos | 1 | 0 | 1 |
| Brown Thrasher Toxostoma rufum | Northern Mockingbird Mimus polyglottos | 1 | 0 | 1 |
| Brown Thrasher Toxostoma rufum | Veery Catharus fuscescens | 1 | 1 | 0 |
| Townsend's Solitaire Myadestes townsendi | Veery Catharus fuscescens | 1 | 0 | 1 |
| Townsend's Solitaire Myadestes townsendi | Grey-cheeked Thrush Catharus minimus | 1 | 1 | 0 |
| Bicknell's Thrush Catharus bicknelli | Hermit Thrush Catharus guttatus | 1 | 1 | 0 |
| Hermit Thrush Catharus guttatus | Wood Thrush Hylocichla mustelina | 1 | 1 | 0 |
| Northern Wheatear Oenanthe oenanthe | Zebra Finch Taeniopygia guttata | 1 | 1 | 0 |
| Evening Grosbeak Hesperiphona vespertina | Pine Grosbeak Pinicola enucleator | 1 | 1 | 0 |
| Pine Siskin Spinus pinus | American Goldfinch Spinus tristis | 1 | 1 | 0 |
| American Goldfinch Spinus tristis | White-crowned Sparrow Zonotrichia leucophrys | 1 | 0 | 1 |
| Lapland Bunting Calcarius lapponicus | Snow Bunting Plectrophenax nivalis | 1 | 0 | 1 |
| Grasshopper Sparrow Ammodramus savannarum | Field Sparrow Spizella pusilla | 1 | 1 | 0 |
| Clay-coloured Sparrow Spizella pallida | Brewer's Sparrow Spizella breweri | 1 | 1 | 0 |
| Lark Bunting Calamospiza melanocorys | Fox Sparrow Passerella iliaca | 1 | 1 | 0 |
| Nelson's Sparrow Ammospiza nelsoni | Savannah Sparrow Passerculus sandwichensis | 1 | 1 | 0 |
| Song Sparrow Melospiza melodia | Lincoln's Sparrow Melospiza lincolnii | 1 | 0 | 1 |
| Red-winged Blackbird Agelaius phoeniceus | Brown-headed Cowbird Molothrus ater | 1 | 1 | 0 |
| Brown-headed Cowbird Molothrus ater | Bay-breasted Warbler Setophaga castanea | 1 | 1 | 0 |
| Prothonotary Warbler Protonotaria citrea | Orange-crowned Warbler Leiothlypis celata | 1 | 1 | 0 |
| Prothonotary Warbler Protonotaria citrea | Common Yellowthroat Geothlypis trichas | 1 | 1 | 0 |
| Virginia's Warbler Leiothlypis virginiae | Mourning Warbler Geothlypis philadelphia | 1 | 0 | 1 |
| MacGillivray's Warbler Geothlypis tolmiei | Mourning Warbler Geothlypis philadelphia | 1 | 1 | 0 |
| Cerulean Warbler Setophaga cerulea | Bay-breasted Warbler Setophaga castanea | 1 | 1 | 0 |
| Magnolia Warbler Setophaga magnolia | Bay-breasted Warbler Setophaga castanea | 1 | 0 | 1 |
| Bay-breasted Warbler Setophaga castanea | Chestnut-sided Warbler Setophaga pensylvanica | 1 | 0 | 1 |
| Blackburnian Warbler Setophaga fusca | Blackpoll Warbler Setophaga striata | 1 | 0 | 1 |
| Black-throated Blue Warbler Setophaga caerulescens | Pine Warbler Setophaga pinus | 1 | 1 | 0 |
| Palm Warbler Setophaga palmarum | Yellow-throated Warbler Setophaga dominica | 1 | 1 | 0 |
| Townsend's Warbler Setophaga townsendi | Hermit Warbler Setophaga occidentalis | 1 | 0 | 1 |
| Townsend's Warbler Setophaga townsendi | Black-throated Green Warbler Setophaga virens | 1 | 1 | 0 |
| Townsend's Warbler Setophaga townsendi | Canada Warbler Cardellina canadensis | 1 | 1 | 0 |
| Lazuli Bunting Passerina amoena | Painted Bunting Passerina ciris | 1 | 1 | 0 |
| Bar-headed Goose Anser indicus | Barrow's Goldeneye Bucephala islandica | 1 | 1 | 0 |
| Painted Bunting Passerina ciris | Dickcissel Spiza americana | 1 | 1 | 0 |
| Cackling Goose Branta hutchinsii | Canada Goose Branta canadensis | 1 | 0 | 1 |
| Canada Goose Branta canadensis | Black Swan Cygnus atratus | 1 | 0 | 1 |
| Muscovy Duck Cairina moschata | Surf Scoter Melanitta perspicillata | 1 | 0 | 1 |
| Ringed Teal Callonetta leucophrys | Northern Pintail Anas acuta | 1 | 1 | 0 |
| Maned Duck Chenonetta jubata | Garganey Spatula querquedula | 1 | 0 | 1 |
| Maned Duck Chenonetta jubata | Bufflehead Bucephala albeola | 1 | 0 | 1 |
| Garganey Spatula querquedula | Blue-winged Teal Spatula discors | 1 | 1 | 0 |
| Blue-winged Teal Spatula discors | Cinnamon Teal Spatula cyanoptera | 1 | 0 | 1 |
| Blue-winged Teal Spatula discors | Gadwall Mareca strepera | 1 | 1 | 0 |
| Cinnamon Teal Spatula cyanoptera | House Finch Haemorhous mexicanus | 1 | 0 | 1 |
| Northern Shoveler Spatula clypeata | Common Goldeneye Bucephala clangula | 1 | 0 | 1 |
| Gadwall Mareca strepera | Red-crested Pochard Netta rufina | 1 | 0 | 1 |
| Gadwall Mareca strepera | Greater Scaup Aythya marila | 1 | 0 | 1 |
| American Black Duck Anas rubripes | Mottled Duck Anas fulvigula | 1 | 1 | 0 |
| Mottled Duck Anas fulvigula | Northern Pintail Anas acuta | 1 | 0 | 1 |
| Mottled Duck Anas fulvigula | Red-crested Pochard Netta rufina | 1 | 1 | 0 |
| Mottled Duck Anas fulvigula | Common Eider Somateria mollissima | 1 | 1 | 0 |
| Eurasian/Green-winged Teal Anas crecca | Ancient Murrelet Synthliboramphus antiquus | 1 | 0 | 1 |
| Red-crested Pochard Netta rufina | Redhead Aythya americana | 1 | 1 | 0 |
| Redhead Aythya americana | Common Eider Somateria mollissima | 1 | 1 | 0 |