- Cabanis's Bunting
- Cabanis's Wren
- Calandra Lark
- Campo Flicker
- Campo Troupial
- Canada Goose
- Canary Flyrobin
- Canary White-eye
- Canivet's Emerald
- Cape Barren Goose
- Cape Batis
- Cape Canary
- Cape Crow
- Cape Longclaw
- Cape Petrel
- Cape Robin-Chat
- Cape Shoveler
- Cape Sparrow
- Cape Starling
- Cape Teal
- Cape Wagtail
- Cape White-eye
- Capped Wheatear
- Capped White-eye
- Cardinal Woodpecker
- Carib Grackle
- Carmelite Sunbird
- Carmiol's Tanager
- Carp's Tit
- Carrion Crow
- Carunculated Caracara
- Caspian Gull
- Caspian Tern
- Cassin's Flycatcher
- Cassin's Kingbird
- Cattle Tyrant
- Cave Swallow
- Cerulean Kingfisher
- Chabert Vanga
- Chaco Puffbird
- Chalk-browed Mockingbird
- Changeable Hawk-Eagle
- Channel-billed Cuckoo
- Channel-billed Toucan
- Chat Flycatcher
- Chattering Cisticola
- Chattering Lory
- Checker-throated Woodpecker
- Chestnut-backed Antbird
- Chestnut-backed Antshrike
- Chestnut-backed Scimitar Babbler
- Chestnut-backed Sparrow-Lark
- Chestnut-backed Thrush
- Chestnut-banded Plover
- Chestnut-bellied Euphonia
- Chestnut-bellied Nuthatch
- Chestnut-bellied Rock Thrush
- Chestnut-bellied Sandgrouse
- Chestnut-bellied Seed Finch
- Chestnut-bellied Seedeater
- Chestnut-bellied Starling
- Chestnut-breasted Coronet
- Chestnut-breasted Malkoha
- Chestnut-breasted Mannikin
- Chestnut-breasted Nigrita
- Chestnut-capped Babbler
- Chestnut-capped Blackbird
- Chestnut-capped Brushfinch
- Chestnut-capped Thrush
- Chestnut-colored Woodpecker
- Chestnut-crowned Becard
- Chestnut-crowned Laughingthrush
- Chestnut-crowned Sparrow-Weaver
- Chestnut-crowned Warbler
- Chestnut-eared Aracari
- Chestnut-fronted Helmetshrike
- Chestnut-headed Bee-eater
- Chestnut-headed Oropendola
- Chestnut-headed Sparrow-Lark
- Chestnut-headed Tesia
- Chestnut-naped Forktail
- Chestnut-naped Francolin
- Chestnut-rumped Babbler
- Chestnut-rumped Heathwren
- Chestnut-rumped Thornbill
- Chestnut-tailed Starling
- Chestnut-throated Seedeater
- Chestnut-vented Conebill
- Chestnut-vented Nuthatch
- Chestnut-vented Warbler
- Chestnut-winged Babbler
- Chestnut-winged Cinclodes
- Chestnut-winged Starling
- Chestnut Munia
- Chestnut Quail-thrush
- Chestnut Sparrow
- Chestnut Teal
- Chestnut Wattle-eye
- Chestnut Weaver
- Chinese Pond Heron
- Chinspot Batis
- Chinstrap Penguin
- Chirping Cisticola
- Choco Toucan
- Choco Warbler
- Chocolate-backed Kingfisher
- Chopi Blackbird
- Chowchilla
- Chukar Partridge
- Cinereous Bulbul
- Cinereous Conebill
- Cinereous Finch
- Cinereous Tinamou
- Cinereous Tit
- Cinnamon-banded Kingfisher
- Cinnamon-bellied Flowerpiercer
- Cinnamon-bellied Imperial Pigeon
- Cinnamon-breasted Bunting
- Cinnamon-chested Bee-eater
- Cinnamon-tailed Sparrow
- Cinnamon Attila
- Cinnamon Becard
- Cinnamon Bittern
- Cinnamon Flycatcher
- Cinnamon Screech Owl
- Cinnamon Tanager
- Cinnamon Teal
- Cirl Bunting
- Citreoline Trogon
- Citrine Canary-flycatcher
- Citrine Lorikeet
- Citrine Wagtail
- Citrine Warbler
- Citron-headed Yellow Finch
- Clamorous Reed Warbler
- Clapperton's Francolin
- Claret-breasted Fruit Dove
- Clay-colored Sparrow
- Clay-colored Thrush
- Cliff Flycatcher
- Coal Tit
- Coastal Miner
- Cobalt-winged Parakeet
- Cockatiel
- Cocoa Woodcreeper
- Cocoi Heron
- Coconut Lorikeet
- Colima Pygmy Owl
- Collared Aracari
- Collared Forest Falcon
- Collared Grosbeak
- Collared Inca
- Collared Kingfisher
- Collared Nightjar
- Collared Owlet
- Collared Plover
- Collared Pratincole
- Collared Sparrowhawk
- Collared Sunbird
- Collared Towhee
- Collared Treepie
- Collared Trogon
- Collared Warbling Finch
- Comb-crested Jacana
- Common Babbler
- Common Black Hawk
- Common Blackbird
- Common Bronzewing
- Common Bulbul
- Common Bush Tanager
- Common Buzzard
- Common Cactus Finch
- Common Chaffinch
- Common Chiffchaff
- Common Cicadabird
- Common Crane
- Common Cuckoo
- Common Eider
- Common Emerald Dove
- Common Flameback
- Common Gallinule
- Common Goldeneye
- Common Green Magpie
- Common Greenshank
- Common Ground Dove
- Common Hawk-Cuckoo
- Common Hill Myna
- Common House Martin
- Common Iora
- Common Jery
- Common Kestrel
- Common Kingfisher
- Common Linnet
- Common Merganser
- Common Moorhen
- Common Murre
- Common Myna
- Common Newtonia
- Common Nightingale
- Common Ostrich
- Common Paradise Kingfisher
- Common Pheasant
- Common Pochard
- Common Potoo
- Common Redpoll
- Common Redshank
- Common Redstart
- Common Reed Bunting
- Common Ringed Plover
- Common Rock Thrush
- Common Rosefinch
- Common Sandpiper
- Common Scimitarbill
- Common Shelduck
- Common Smoky Honeyeater
- Common Snipe
- Common Square-tailed Drongo
- Common Starling
- Common Sunbird-Asity
- Common Swift
- Common Tailorbird
- Common Tern
- Common Tody-Flycatcher
- Common Waxbill
- Common Whitethroat
- Common Wood Pigeon
- Common Woodshrike
- Common Yellowthroat
- Comoros Blue Pigeon
- Comoros Cuckooshrike
- Comoros Fody
- Comoros Green Pigeon
- Comoros Olive Pigeon
- Comoros Thrush
- Congo Moor Chat
- Copper Sunbird
- Coppersmith Barbet
- Coquerel's Coua
- Coqui Francolin
- Cordilleran Canastero
- Cordilleran Flycatcher
- Corn Bunting
- Corn Crake
- Coscoroba Swan
- Cotton Pygmy Goose
- Couch's Kingbird
- Crab-plover
- Cream-browed White-eye
- Cream-colored Courser
- Cream-colored Woodpecker
- Cream-throated White-eye
- Cream-vented Bulbul
- Cream-winged Cinclodes
- Creamy-bellied Thrush
- Crescent-chested Puffbird
- Crescent-chested Warbler
- Crescent Honeyeater
- Crested Barbet
- Crested Becard
- Crested Bellbird
- Crested Berrypecker
- Crested Bunting
- Crested Coua
- Crested Drongo
- Crested Duck
- Crested Finchbill
- Crested Francolin
- Crested Goshawk
- Crested Guan
- Crested Guineafowl
- Crested Honey Buzzard
- Crested Kingfisher
- Crested Lark
- Crested Malimbe
- Crested Myna
- Crested Oropendola
- Crested Pigeon
- Crested Quetzal
- Crested Serpent Eagle
- Crested Shriketit
- Crested White-eye
- Cricket Warbler
- Crimson-backed Sunbird
- Crimson-breasted Flowerpecker
- Crimson-breasted Woodpecker
- Crimson-browed Finch
- Crimson-collared Tanager
- Crimson-hooded Manakin
- Crimson-mantled Woodpecker
- Crimson-rumped Toucanet
- Crimson-winged Woodpecker
- Crimson Finch
- Crimson Rosella
- Crimson Sunbird
- Croaking Cisticola
- Croaking Ground Dove
- Crossley's Vanga
- Crow-billed Drongo
- Crowned Hornbill
- Crowned Lapwing
- Crowned Sandgrouse
- Crowned Woodnymph
- Cryptic Warbler
- Cuckoo Roller
- Curlew Sandpiper
- Curve-billed Thrasher
- Cut-throat Finch