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 |
|---|---|---|---|---|
| Southern Pochard Netta erythrophthalma | Ring-necked Duck Aythya collaris | 3 | 3 | 0 |
| Western Meadowlark Sturnella neglecta | Eastern Meadowlark Sturnella magna | 3 | 3 | 0 |
| Lazuli Bunting Passerina amoena | Dickcissel Spiza americana | 2 | 2 | 0 |
| Common Goldeneye Bucephala clangula | Barrow's Goldeneye Bucephala islandica | 2 | 0 | 2 |
| Band-tailed Pigeon Patagioenas fasciata | Inca Dove Columbina inca | 2 | 2 | 0 |
| Anna's Hummingbird Calypte anna | Calliope Hummingbird Selasphorus calliope | 2 | 0 | 2 |
| American Moorhen Gallinula galeata | Purple Gallinule Porphyrio martinica | 2 | 0 | 2 |
| Sanderling Calidris alba | Purple Sandpiper Calidris maritima | 2 | 2 | 0 |
| Long-tailed Skua Stercorarius longicaudus | Pomarine Skua Stercorarius pomarinus | 2 | 0 | 2 |
| Lesser Black-backed Gull Larus fuscus | California Gull Larus californicus | 2 | 0 | 2 |
| Arctic Tern Sterna paradisaea | Royal Tern Thalasseus maximus | 2 | 2 | 0 |
| Common Tern Sterna hirundo | Sandwich Tern Thalasseus sandvicensis | 2 | 2 | 0 |
| Great Cormorant Phalacrocorax carbo | Double-crested Cormorant Nannopterum auritum | 2 | 2 | 0 |
| Great Cormorant Phalacrocorax carbo | Neotropic Cormorant Nannopterum brasilianum | 2 | 2 | 0 |
| Glossy Ibis Plegadis falcinellus | White-faced Ibis Plegadis chihi | 2 | 0 | 2 |
| Red-shouldered Hawk Buteo lineatus | Swainson's Hawk Buteo swainsoni | 2 | 2 | 0 |
| Cassin's Kingbird Tyrannus vociferans | Eastern Kingbird Tyrannus tyrannus | 2 | 0 | 2 |
| Hermit Thrush Catharus guttatus | Wood Thrush Hylocichla mustelina | 2 | 0 | 2 |
| Common Crossbill Loxia curvirostra | Two-barred Crossbill Loxia leucoptera | 2 | 0 | 2 |
| Lapland Bunting Calcarius lapponicus | Thick-billed Longspur Rhynchophanes mccownii | 2 | 0 | 2 |
| Grasshopper Sparrow Ammodramus savannarum | Clay-coloured Sparrow Spizella pallida | 2 | 0 | 2 |
| Chipping Sparrow Spizella passerina | Field Sparrow Spizella pusilla | 2 | 0 | 2 |
| Brewer's Blackbird Euphagus cyanocephalus | Common Grackle Quiscalus quiscula | 2 | 2 | 0 |
| Worm-eating Warbler Helmitheros vermivorum | Northern Waterthrush Parkesia noveboracensis | 2 | 2 | 0 |
| Connecticut Warbler Oporornis agilis | Kentucky Warbler Geothlypis formosa | 2 | 2 | 0 |
| Lazuli Bunting Passerina amoena | Painted Bunting Passerina ciris | 1 | 1 | 0 |
| American Coot Fulica americana | Purple Gallinule Porphyrio martinica | 1 | 0 | 1 |
| Black Rail Laterallus jamaicensis | Limpkin Aramus guarauna | 1 | 0 | 1 |
| Hooded Crane Grus monacha | Whooping Crane Grus americana | 1 | 1 | 0 |
| American Avocet Recurvirostra americana | Semipalmated Plover Charadrius semipalmatus | 1 | 1 | 0 |
| Killdeer Charadrius vociferus | Semipalmated Plover Charadrius semipalmatus | 1 | 0 | 1 |
| Semipalmated Plover Charadrius semipalmatus | Snowy Plover Anarhynchus nivosus | 1 | 1 | 0 |
| Long-billed Curlew Numenius americanus | Marbled Godwit Limosa fedoa | 1 | 1 | 0 |
| Long-billed Curlew Numenius americanus | Long-billed Dowitcher Limnodromus scolopaceus | 1 | 1 | 0 |
| Hudsonian Godwit Limosa haemastica | Long-billed Dowitcher Limnodromus scolopaceus | 1 | 1 | 0 |
| Marbled Godwit Limosa fedoa | Short-billed Dowitcher Limnodromus griseus | 1 | 1 | 0 |
| Marbled Godwit Limosa fedoa | Long-billed Dowitcher Limnodromus scolopaceus | 1 | 1 | 0 |
| Spotted Sandpiper Actitis macularius | Solitary Sandpiper Tringa solitaria | 1 | 0 | 1 |
| Solitary Sandpiper Tringa solitaria | Lesser Yellowlegs Tringa flavipes | 1 | 1 | 0 |
| Ruddy Turnstone Arenaria interpres | Red Knot Calidris canutus | 1 | 0 | 1 |
| Ruff Calidris pugnax | Sharp-tailed Sandpiper Calidris acuminata | 1 | 0 | 1 |
| Sharp-tailed Sandpiper Calidris acuminata | Red-necked Stint Calidris ruficollis | 1 | 1 | 0 |
| Louisiana Waterthrush Parkesia motacilla | Northern Waterthrush Parkesia noveboracensis | 1 | 1 | 0 |
| Baird's Sandpiper Calidris bairdii | White-rumped Sandpiper Calidris fuscicollis | 1 | 1 | 0 |
| Western Sandpiper Calidris mauri | Semipalmated Sandpiper Calidris pusilla | 1 | 1 | 0 |
| Snow Goose Anser caerulescens | Ross's Goose Anser rossii | 1 | 0 | 1 |
| Arctic Skua Stercorarius parasiticus | Pomarine Skua Stercorarius pomarinus | 1 | 1 | 0 |
| Pomarine Skua Stercorarius pomarinus | South Polar Skua Stercorarius maccormicki | 1 | 1 | 0 |
| Chestnut-sided Warbler Setophaga pensylvanica | Black-throated Blue Warbler Setophaga caerulescens | 1 | 0 | 1 |
| Forster's Tern Sterna forsteri | Common Tern Sterna hirundo | 1 | 0 | 1 |
| Yellow-throated Warbler Setophaga dominica | Prairie Warbler Setophaga discolor | 1 | 0 | 1 |
| Yellow-headed Blackbird Xanthocephalus xanthocephalus | Bobolink Dolichonyx oryzivorus | 1 | 1 | 0 |
| Red-throated Diver Gavia stellata | Pacific Diver Gavia pacifica | 1 | 1 | 0 |
| Red-throated Diver Gavia stellata | White-billed Diver Gavia adamsii | 1 | 1 | 0 |
| Magnificent Frigatebird Fregata magnificens | Anhinga Anhinga anhinga | 1 | 1 | 0 |
| Magnificent Frigatebird Fregata magnificens | Double-crested Cormorant Nannopterum auritum | 1 | 1 | 0 |
| Brent Goose Branta bernicla | Barnacle Goose Branta leucopsis | 1 | 1 | 0 |
| Red-winged Blackbird Agelaius phoeniceus | Shiny Cowbird Molothrus bonariensis | 1 | 0 | 1 |
| Black-crowned Night Heron Nycticorax nycticorax | Tricoloured Heron Egretta tricolor | 1 | 0 | 1 |
| Tricoloured Heron Egretta tricolor | Reddish Egret Egretta rufescens | 1 | 1 | 0 |
| Shiny Cowbird Molothrus bonariensis | Bronzed Cowbird Molothrus aeneus | 1 | 1 | 0 |
| Snail Kite Rostrhamus sociabilis | Northern Harrier Circus hudsonius | 1 | 0 | 1 |
| Mississippi Kite Ictinia mississippiensis | Northern Harrier Circus hudsonius | 1 | 0 | 1 |
| Red-shouldered Hawk Buteo lineatus | Broad-winged Hawk Buteo platypterus | 1 | 1 | 0 |
| Shiny Cowbird Molothrus bonariensis | Brown-headed Cowbird Molothrus ater | 1 | 1 | 0 |
| Short-eared Owl Asio flammeus | Northern Saw-whet Owl Aegolius acadicus | 1 | 1 | 0 |
| Eastern Wood-Pewee Contopus virens | Acadian Flycatcher Empidonax virescens | 1 | 0 | 1 |
| Acadian Flycatcher Empidonax virescens | Least Flycatcher Empidonax minimus | 1 | 1 | 0 |
| Willow Flycatcher Empidonax traillii | Western Flycatcher Empidonax difficilis | 1 | 1 | 0 |
| Blue Grosbeak Passerina caerulea | Lazuli Bunting Passerina amoena | 1 | 0 | 1 |
| White-eyed Vireo Vireo griseus | Blue-headed Vireo Vireo solitarius | 1 | 0 | 1 |
| Bell's Vireo Vireo bellii | Blue-headed Vireo Vireo solitarius | 1 | 0 | 1 |
| Purple Martin Progne subis | American Goldfinch Spinus tristis | 1 | 0 | 1 |
| Ruby-crowned Kinglet Corthylio calendula | Golden-crowned Kinglet Regulus satrapa | 1 | 1 | 0 |
| South African Shelduck Tadorna cana | Paradise Shelduck Tadorna variegata | 1 | 0 | 1 |
| Paradise Shelduck Tadorna variegata | Common Shelduck Tadorna tadorna | 1 | 1 | 0 |
| Mallard Anas platyrhynchos | American Black Duck Anas rubripes | 1 | 0 | 1 |
| American Black Duck Anas rubripes | Mottled Duck Anas fulvigula | 1 | 0 | 1 |
| American Black Duck Anas rubripes | Northern Pintail Anas acuta | 1 | 1 | 0 |
| Southern Pochard Netta erythrophthalma | Canvasback Aythya valisineria | 1 | 1 | 0 |
| Southern Pochard Netta erythrophthalma | Redhead Aythya americana | 1 | 1 | 0 |
| Ruddy Shelduck Tadorna ferruginea | Common Shelduck Tadorna tadorna | 1 | 1 | 0 |
| Surf Scoter Melanitta perspicillata | White-winged Scoter Melanitta deglandi | 1 | 1 | 0 |
| Surf Scoter Melanitta perspicillata | Black Scoter Melanitta americana | 1 | 1 | 0 |
| Bufflehead Bucephala albeola | Common Goldeneye Bucephala clangula | 1 | 0 | 1 |
| Brown Thrasher Toxostoma rufum | Sage Thrasher Oreoscoptes montanus | 1 | 0 | 1 |
| Barrow's Goldeneye Bucephala islandica | Hooded Merganser Lophodytes cucullatus | 1 | 1 | 0 |
| Barrow's Goldeneye Bucephala islandica | Goosander Mergus merganser | 1 | 1 | 0 |
| Western Grebe Aechmophorus occidentalis | Clark's Grebe Aechmophorus clarkii | 1 | 0 | 1 |
| Townsend's Solitaire Myadestes townsendi | Varied Thrush Ixoreus naevius | 1 | 0 | 1 |
| Common Nighthawk Chordeiles minor | Eastern Whip-poor-will Antrostomus vociferus | 1 | 0 | 1 |
| Chuck-will's-widow Antrostomus carolinensis | Eastern Whip-poor-will Antrostomus vociferus | 1 | 0 | 1 |
| Veery Catharus fuscescens | Hermit Thrush Catharus guttatus | 1 | 0 | 1 |
| Calliope Hummingbird Selasphorus calliope | Broad-tailed Hummingbird Selasphorus platycercus | 1 | 0 | 1 |
| Allen's Hummingbird Selasphorus sasin | Broad-tailed Hummingbird Selasphorus platycercus | 1 | 0 | 1 |
| King Rail Rallus elegans | Virginia Rail Rallus limicola | 1 | 1 | 0 |