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 |
|---|---|---|---|---|
| Black-chinned Hummingbird Archilochus alexandri | Calliope Hummingbird Selasphorus calliope | 2 | 2 | 0 |
| Ringed Teal Callonetta leucophrys | Wood Duck Aix sponsa | 1 | 1 | 0 |
| Cinnamon Teal Spatula cyanoptera | Mississippi Kite Ictinia mississippiensis | 1 | 1 | 0 |
| American Wigeon Mareca americana | Fish Crow Corvus ossifragus | 1 | 1 | 0 |
| Northern Pintail Anas acuta | Royal Tern Thalasseus maximus | 1 | 1 | 0 |
| Greater Scaup Aythya marila | Swainson's Hawk Buteo swainsoni | 1 | 0 | 1 |
| Black Scoter Melanitta americana | Black-throated Grey Warbler Setophaga nigrescens | 1 | 1 | 0 |
| Bufflehead Bucephala albeola | Common Goldeneye Bucephala clangula | 1 | 1 | 0 |
| Common Goldeneye Bucephala clangula | Hammond's Flycatcher Empidonax hammondii | 1 | 0 | 1 |
| Red-breasted Merganser Mergus serrator | Belted Kingfisher Megaceryle alcyon | 1 | 1 | 0 |
| Northern Bobwhite Colinus virginianus | Pomarine Skua Stercorarius pomarinus | 1 | 0 | 1 |
| Wild Turkey Meleagris gallopavo | Western Tanager Piranga ludoviciana | 1 | 1 | 0 |
| Ruffed Grouse Bonasa umbellus | Little Auk Alle alle | 1 | 0 | 1 |
| Passenger Pigeon Ectopistes migratorius | African Collared Dove Streptopelia roseogrisea | 1 | 1 | 0 |
| Common Ground Dove Columbina passerina | Mourning Dove Zenaida macroura | 1 | 1 | 0 |
| Chuck-will's-widow Antrostomus carolinensis | Indigo Bunting Passerina cyanea | 1 | 0 | 1 |
| Black-chinned Hummingbird Archilochus alexandri | Broad-tailed Hummingbird Selasphorus platycercus | 1 | 0 | 1 |
| Clapper Rail Rallus crepitans | Sora Porzana carolina | 1 | 1 | 0 |
| Sora Porzana carolina | Orange-crowned Warbler Leiothlypis celata | 1 | 1 | 0 |
| American Oystercatcher Haematopus palliatus | Spotted Towhee Pipilo maculatus | 1 | 1 | 0 |
| Pacific Golden Plover Pluvialis fulva | Northern Lapwing Vanellus vanellus | 1 | 1 | 0 |
| Long-billed Curlew Numenius americanus | American Goldfinch Spinus tristis | 1 | 0 | 1 |
| Bar-tailed Godwit Limosa lapponica | Orange-crowned Warbler Leiothlypis celata | 1 | 1 | 0 |
| Short-billed Dowitcher Limnodromus griseus | Fork-tailed Flycatcher Tyrannus savana | 1 | 1 | 0 |
| American Woodcock Scolopax minor | Wilson's Snipe Gallinago delicata | 1 | 0 | 1 |
| Wilson's Phalarope Phalaropus tricolor | Ovenbird Seiurus aurocapilla | 1 | 1 | 0 |
| Red-necked Phalarope Phalaropus lobatus | Black Skimmer Rynchops niger | 1 | 0 | 1 |
| Willet Tringa semipalmata | American Kestrel Falco sparverius | 1 | 1 | 0 |
| Ruddy Turnstone Arenaria interpres | Brown Thrasher Toxostoma rufum | 1 | 0 | 1 |
| Red Knot Calidris canutus | Eastern Screech-Owl Megascops asio | 1 | 1 | 0 |
| Dunlin Calidris alpina | Marsh Wren Cistothorus palustris | 1 | 1 | 0 |
| Long-tailed Skua Stercorarius longicaudus | Hooded Warbler Setophaga citrina | 1 | 1 | 0 |
| Pomarine Skua Stercorarius pomarinus | Boreal Chickadee Poecile hudsonicus | 1 | 1 | 0 |
| Pomarine Skua Stercorarius pomarinus | Dickcissel Spiza americana | 1 | 0 | 1 |
| Brünnich's Guillemot Uria lomvia | Great Shearwater Ardenna gravis | 1 | 1 | 0 |
| Common Guillemot Uria aalge | Magnificent Frigatebird Fregata magnificens | 1 | 0 | 1 |
| Bonaparte's Gull Chroicocephalus philadelphia | Brewer's Sparrow Spizella breweri | 1 | 0 | 1 |
| Laughing Gull Leucophaeus atricilla | Sandwich Tern Thalasseus sandvicensis | 1 | 0 | 1 |
| Franklin's Gull Leucophaeus pipixcan | Common Tern Sterna hirundo | 1 | 0 | 1 |
| Black Skimmer Rynchops niger | Orange-fronted Parakeet Eupsittula canicularis | 1 | 1 | 0 |
| Least Tern Sternula antillarum | Nelson's Sparrow Ammospiza nelsoni | 1 | 1 | 0 |
| Roseate Tern Sterna dougallii | Cory's Shearwater Calonectris borealis | 1 | 1 | 0 |
| Red-billed Tropicbird Phaethon aethereus | Common Yellowthroat Geothlypis trichas | 1 | 0 | 1 |
| Red-throated Diver Gavia stellata | Great Northern Diver Gavia immer | 1 | 1 | 0 |
| Black-browed Albatross Thalassarche melanophris | Tree Swallow Tachycineta bicolor | 1 | 1 | 0 |
| European Storm-Petrel Hydrobates pelagicus | Eastern Wood-Pewee Contopus virens | 1 | 1 | 0 |
| Band-rumped Storm-Petrel Hydrobates castro | Alder Flycatcher Empidonax alnorum | 1 | 1 | 0 |
| Northern Fulmar Fulmarus glacialis | Veery Catharus fuscescens | 1 | 0 | 1 |
| Great Shearwater Ardenna gravis | Swainson's Thrush Catharus ustulatus | 1 | 1 | 0 |
| Yellow-crowned Night Heron Nyctanassa violacea | Cliff Swallow Petrochelidon pyrrhonota | 1 | 0 | 1 |
| Western Cattle-Egret Ardea ibis | Great Crested Flycatcher Myiarchus crinitus | 1 | 0 | 1 |
| Broad-winged Hawk Buteo platypterus | Swainson's Hawk Buteo swainsoni | 1 | 0 | 1 |
| Swainson's Hawk Buteo swainsoni | Red-tailed Hawk Buteo jamaicensis | 1 | 1 | 0 |
| American Barn Owl Tyto furcata | Eastern Phoebe Sayornis phoebe | 1 | 0 | 1 |
| Red-bellied Woodpecker Melanerpes carolinus | Northern Mockingbird Mimus polyglottos | 1 | 1 | 0 |
| Saker Falcon Falco cherrug | Gyr Falcon Falco rusticolus | 1 | 0 | 1 |
| Red-headed Lovebird Agapornis pullarius | Prothonotary Warbler Protonotaria citrea | 1 | 1 | 0 |
| Olive-sided Flycatcher Contopus cooperi | Willow Flycatcher Empidonax traillii | 1 | 1 | 0 |
| Olive-sided Flycatcher Contopus cooperi | Kentucky Warbler Geothlypis formosa | 1 | 0 | 1 |
| Alder Flycatcher Empidonax alnorum | Northern Rough-winged Swallow Stelgidopteryx serripennis | 1 | 0 | 1 |
| Willow Flycatcher Empidonax traillii | Scissor-tailed Flycatcher Tyrannus forficatus | 1 | 1 | 0 |
| Least Flycatcher Empidonax minimus | Yellow-rumped Warbler Setophaga coronata | 1 | 1 | 0 |
| Hammond's Flycatcher Empidonax hammondii | Ash-throated Flycatcher Myiarchus cinerascens | 1 | 1 | 0 |
| Cassin's Kingbird Tyrannus vociferans | Two-barred Crossbill Loxia leucoptera | 1 | 1 | 0 |
| Blue-headed Vireo Vireo solitarius | Brown Creeper Certhia americana | 1 | 1 | 0 |
| Philadelphia Vireo Vireo philadelphicus | Red-eyed Vireo Vireo olivaceus | 1 | 0 | 1 |
| Carolina Chickadee Poecile carolinensis | White-crowned Sparrow Zonotrichia leucophrys | 1 | 0 | 1 |
| Tree Swallow Tachycineta bicolor | Violet-green Swallow Tachycineta thalassina | 1 | 0 | 1 |
| Northern House Wren Troglodytes aedon | Sedge Wren Cistothorus stellaris | 1 | 0 | 1 |
| Sedge Wren Cistothorus stellaris | Yellow-breasted Chat Icteria virens | 1 | 1 | 0 |
| Carolina Wren Thryothorus ludovicianus | Atlantic Canary Serinus canaria | 1 | 1 | 0 |
| Brown Thrasher Toxostoma rufum | Sage Thrasher Oreoscoptes montanus | 1 | 0 | 1 |
| Townsend's Solitaire Myadestes townsendi | Varied Thrush Ixoreus naevius | 1 | 1 | 0 |
| Swainson's Thrush Catharus ustulatus | Hermit Thrush Catharus guttatus | 1 | 1 | 0 |
| Northern Wheatear Oenanthe oenanthe | Canada Warbler Cardellina canadensis | 1 | 0 | 1 |
| Lapland Bunting Calcarius lapponicus | American Redstart Setophaga ruticilla | 1 | 1 | 0 |
| Brewer's Sparrow Spizella breweri | Spotted Towhee Pipilo maculatus | 1 | 1 | 0 |
| Lark Bunting Calamospiza melanocorys | Seaside Sparrow Ammospiza maritima | 1 | 1 | 0 |
| Nelson's Sparrow Ammospiza nelsoni | Savannah Sparrow Passerculus sandwichensis | 1 | 1 | 0 |
| Orchard Oriole Icterus spurius | Bullock's Oriole Icterus bullockii | 1 | 1 | 0 |
| Blackburnian Warbler Setophaga fusca | Blackpoll Warbler Setophaga striata | 1 | 0 | 1 |
| Yellow-rumped Warbler Setophaga coronata | Indigo Bunting Passerina cyanea | 1 | 0 | 1 |
| Ross's Goose Anser rossii | Long-tailed Duck Clangula hyemalis | 1 | 0 | 1 |
| Canada Warbler Cardellina canadensis | Summer Tanager Piranga rubra | 1 | 1 | 0 |