- California Gull
- California Quail
- Canada Goose
- Canada Jay
- Canary Islands Chiffchaff
- Canivet's Emerald
- Cape Bulbul
- Cape Bunting
- Cape Canary
- Cape Cormorant
- Cape Crow
- Cape Eagle-Owl
- Cape Gannet
- Cape Grassbird
- Cape May Warbler
- Cape Robin-Chat
- Cape Shoveler
- Cape Sparrow
- Cape Spurfowl
- Cape Starling
- Cape Sugarbird
- Cape Teal
- Cape Wagtail
- Cape Weaver
- Cape White-eye
- Capped Heron
- Cardinal Woodpecker
- Carib Grackle
- Caribbean Elaenia
- Carrion Crow
- Caspian Gull
- Caspian Tern
- Cattle Tyrant
- Cedar Waxwing
- Cetti's Warbler
- Chabert Vanga
- Chalk-browed Mockingbird
- Changeable Hawk-Eagle
- Chestnut-bellied Malkoha
- Chestnut-bellied Sandgrouse
- Chestnut-bellied Seed Finch
- Chestnut-breasted Mountain Finch
- Chestnut-capped Brushfinch
- Chestnut-capped Laughingthrush
- Chestnut-headed Bee-eater
- Chestnut-headed Oropendola
- Chestnut-naped Spurfowl
- Chestnut-winged Cuckoo
- Chiguanco Thrush
- Chilean Elaenia
- Chilean Flamingo
- Chilean Flicker
- Chilean Skua
- Chilean Swallow
- Chiloe Wigeon
- Chimango Caracara
- Chinese Pond Heron
- Chinspot Batis
- Chipping Sparrow
- Chorister Robin-Chat
- Cinereous Harrier
- Cinereous Tit
- Cinnamon-breasted Bunting
- Cinnamon-chested Bee-eater
- Cinnamon Bracken Warbler
- Cinnamon Teal
- Cirl Bunting
- Citrine Wagtail
- Clark's Nutcracker
- Clay-colored Thrush
- Cliff Flycatcher
- Coal Tit
- Collared Aracari
- Collared Kingfisher
- Collared Scops Owl
- Collared Sunbird
- Collared Trogon
- Collared Whitestart
- Common Babbler
- Common Black Hawk
- Common Bulbul
- Common Buzzard
- Common Buzzard (vulpinus)
- Common Chiffchaff
- Common Chlorospingus
- Common Crane
- Common Cuckoo
- Common Eider
- Common Firecrest
- Common Flameback
- Common Gallinule
- Common Goldeneye
- Common Grasshopper Warbler
- Common Greenshank
- Common Ground Dove
- Common Gull
- Common Iora
- Common Kestrel
- Common Kingfisher
- Common Linnet
- Common Loon
- Common Merganser
- Common Moorhen
- Common Murre
- Common Myna
- Common Nightingale
- Common Ostrich
- Common Pheasant
- Common Pochard
- Common Redshank
- Common Redstart
- Common Reed Bunting
- Common Reed Warbler
- Common Ringed Plover
- Common Rock Thrush
- Common Rosefinch
- Common Sandpiper
- Common Scoter
- Common Shelduck
- Common Snipe
- Common Starling
- Common Tailorbird
- Common Tern
- Common Tody-Flycatcher
- Common Waxbill
- Common Whitethroat
- Common Wood Pigeon
- Cooper's Hawk
- Coppersmith Barbet
- Coppery-headed Emerald
- Corn Bunting
- Correndera Pipit
- Corsican Finch
- Corsican Nuthatch
- Cory's Shearwater
- Coscoroba Swan
- Cream-winged Cinclodes
- Crested Bobwhite
- Crested Caracara
- Crested Caracara (cheriway)
- Crested Drongo
- Crested Duck
- Crested Francolin
- Crested Guan
- Crested Lark
- Crested Serpent Eagle
- Crimson-backed Flameback
- Crimson-backed Tanager
- Crimson-breasted Shrike
- Crimson-winged Woodpecker
- Croaking Ground Dove
- Crowned Cormorant
- Crowned Lapwing
- Cuban Blackbird
- Cuban Bullfinch
- Cuban Emerald
- Cuban Green Woodpecker
- Cuban Oriole
- Cuban Pewee
- Cuban Tody
- Cuban Trogon
- Curlew Sandpiper
- Cut-throat Finch