- Calandra Lark
- Canada Goose
- Canada Jay
- Canary Islands Chaffinch
- Canary Islands Chiffchaff
- Cape Barren Goose
- Cape Teal
- Carib Grackle
- Carrion Crow
- Caspian Gull
- Caspian Tern
- Cedar Waxwing
- Cetti's Warbler
- Channel-billed Toucan
- Chestnut-headed Bee-eater
- Chestnut-tailed Starling
- Chestnut Teal
- Chilean Flamingo
- Chiloe Wigeon
- Chipping Sparrow
- Chukar Partridge
- Cinereous Bunting
- Cinereous Vulture
- Cirl Bunting
- Citril Finch
- Citrine Wagtail
- Clay-colored Thrush
- Coal Tit
- Cocoi Heron
- Coconut Lorikeet
- Collared Aracari
- Collared Flycatcher
- Collared Plover
- Collared Pratincole
- Common Blackbird
- Common Bronzewing
- Common Bulbul
- Common Buzzard
- Common Chiffchaff
- Common Crane
- Common Cuckoo
- Common Eider
- Common Emerald Dove
- Common Goldeneye
- Common Grackle
- 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 Redpoll
- Common Redshank
- Common Redshank (robusta)
- Common Redstart
- Common Reed Bunting
- Common Reed Warbler
- Common Ringed Plover
- Common Rock Thrush
- Common Sandpiper
- Common Scoter
- Common Shelduck
- Common Snipe
- Common Starling
- Common Swift
- Common Tailorbird
- Common Tern
- Common Tody-Flycatcher
- Common Waxbill
- Common Whitethroat
- Common Wood Pigeon
- Common Yellowthroat
- Coppersmith Barbet
- Corn Bunting
- Cory's Shearwater
- Cream-colored Courser
- Crested Caracara (cheriway)
- Crested Guan
- Crested Lark
- Crested Oropendola
- Crested Partridge
- Crested Pigeon
- Crested Serpent Eagle
- Crested Tit
- Cretzschmar's Bunting
- Crimson-backed Sunbird
- Crimson-hooded Manakin
- Curlew Sandpiper