- Cardinal
- Crow
- Common Sparrow
- Canary
- Cockatoo
- Cuckoo
- Cormorant
- Crane
- Chickadee
- Chaffinch
- Cedar Waxwing
- Common Blackbird
- Common Loon
- Common Myna
- Common Pheasant
- Common Redpoll
- Common Starling
- Condor
- Common Buzzard
- Cattle Egret
- Common Grackle
- Common Kingfisher
- California Condor
- Cetti’s Warbler
- Cape Gannet
- Cape May Warbler
- Cassin’s Finch
- Cedar Waxwing
- Chipping Sparrow
- Cinnamon Teal
- Clark’s Nutcracker
- Cliff Swallow
- Coal Tit
- Collared Aracari
- Collared Dove
- Collared Kingfisher
- Common Tern
- Cooper’s Hawk
- Crested Caracara
- Crested Tit
- Cuban Parrot
- Cuban Tody
- Curlew
- Curl-crested Aracari
- Cape Robin
- Canvasback
- Capercaillie
- Cape May Warbler
- Cape Petrel
- Cape Sparrow
- Capuchinbird
- Cardinal Woodpecker
- Carolina Chickadee
- Carolina Wren
- Carrion Crow
- Cassowary
- Cedar Waxwing
- Cerulean Warbler
- Chestnut-sided Warbler
- Chinese Bulbul
- Chinese Francolin
- Chinese Grosbeak
- Chinese Night Heron
- Chinese Pond Heron
- Chinese Sparrowhawk
- Chinese Thrush
- Chipping Sparrow
- Chuck-will’s-widow
- Cinnamon Teal
- Clark’s Grebe
- Clark’s Nutcracker
- Cliff Swallow
- Clipping Sparrow
- Coal Tit
- Cobalt-winged Parakeet
- Collared Aracari
- Collared Dove
- Collared Kingfisher
- Collie’s Woodpecker
- Columbian Sharp-tailed Grouse
- Common Bulbul
- Common Buzzard
- Common Chaffinch
- Common Cuckoo
- Common Eider
- Common Gallinule
- Common Goldeneye
- Common Grackle
- Common Ground Dove
- Common Guillemot
- Common House Martin
- Common Kestrel
- Common Kingfisher
- Common Loon
- Common Merganser
- Common Moorhen
- Common Nighthawk
- Common Pheasant
- Common Redpoll
- Common Sandpiper
- Common Murre
- Common Pauraque
- Common Raven
- Common Redstart
- Common Ringed Plover
- Common Rosefinch
- Common Sandpiper
- Common Snipe
- Common Swift
- Common Tern
- Common Whitethroat
- Common Yellowthroat
- Connecticut Warbler
- Cook’s Petrel
- Cook’s Swift
- Cooper’s Hawk
- Cordilleran Flycatcher
- Corncrake
- Costa’s Hummingbird
- Couch’s Kingbird
- Crested Auklet
- Crested Caracara
- Crested Falconet
- Crested Francolin
- Crested Guan
- Crested Honey Buzzard
- Crested Kingfisher
- Crested Lark
- Crested Owl
- Crested Pigeon
- Crested Quetzal
- Crested Serpent Eagle
- Crested Shrike-tit
- Crested Tit-Warbler
- Crested Treeswift
- Crimson Sunbird
- Crimson Rosella
- Crimson-breasted Shrike
- Crimson-fronted Barbet
- Crowned Eagle
- Crowned Hornbill
- Cuban Green Woodpecker
- Cuban Oriole
- Cuban Pewee
- Cuban Pygmy Owl
- Cuban Tody
- Curve-billed Thrasher
- Curve-billed Thrasher
- Curve-billed Thrasher
- Cuvier’s Toucan
