- Calandra Lark
- Canada Goose
- Canada Jay
- Canary Islands Stonechat
- Cape Batis
- Cape Bulbul
- Cape Bunting
- Cape Canary
- Cape Cormorant
- Cape Crow
- Cape Eagle-Owl
- Cape Gannet
- Cape Grassbird
- Cape Penduline Tit
- Cape Robin-Chat
- Cape Rockjumper
- Cape Shoveler
- Cape Siskin
- Cape Sparrow
- Cape Spurfowl
- Cape Starling
- Cape Sugarbird
- Cape Teal
- Cape Wagtail
- Cape Weaver
- Cape White-eye
- Capped Wheatear
- Cardinal Woodpecker
- Carib Grackle
- Carrion Crow
- Carruthers's Cisticola
- Caspian Tern
- Cassin's Flycatcher
- Cattle Tyrant
- Cauca Guan
- Cedar Waxwing
- Cetti's Warbler
- Chat Flycatcher
- Chestnut-and-black Weaver
- Chestnut-backed Sparrow-Lark
- Chestnut-bellied Sandgrouse
- Chestnut-breasted Nigrita
- Chestnut-capped Laughingthrush
- Chestnut-capped Warbler
- Chestnut-crowned Antpitta
- Chestnut-headed Bee-eater
- Chestnut-naped Spurfowl
- Chestnut-sided Warbler
- Chestnut-tailed Starling
- Chestnut-vented Nuthatch
- Chestnut-vented Warbler
- Chestnut Sparrow
- Chiguanco Thrush
- Chinese Blue Flycatcher
- Chinese Pond Heron
- Chipping Sparrow
- Chiriqui Quail-Dove
- Chukar Partridge
- Cinereous Conebill
- Cinereous Harrier
- Cinereous Tit
- Cinereous Vulture
- Cinnamon-bellied Saltator
- Cinnamon-breasted Bunting
- Cinnamon-breasted Warbler
- Cinnamon-chested Bee-eater
- Cinnamon Becard
- Cinnamon Teal
- Cinnamon Woodpecker
- Cirl Bunting
- Citril Finch
- Citrine Wagtail
- Clamorous Reed Warbler
- Claudia's Leaf Warbler
- Clay-colored Thrush
- Coal Tit
- Coastal Miner
- Cocoa Woodcreeper
- Collared Aracari
- Collared Flycatcher
- Collared Inca
- Collared Kingfisher
- Collared Pratincole
- Collared Scops Owl
- Collared Sunbird
- Collared Trogon
- Collared Whitestart
- Colombian Chachalaca
- Common Black Hawk
- Common Blackbird
- Common Bulbul
- Common Bulbul (tricolor)
- Common Buzzard
- Common Buzzard (vulpinus)
- Common Chiffchaff
- Common Chlorospingus (ophthalmicus)
- Common Crane
- Common Cuckoo
- Common Eider
- Common Emerald Dove
- Common Firecrest
- Common Flameback
- Common Gallinule
- Common Goldeneye
- Common Grackle
- Common Grasshopper Warbler
- Common Greenshank
- Common Ground Dove
- Common Gull
- Common Hill Myna
- Common Iora
- Common Kestrel
- Common Kingfisher
- Common Linnet
- Common Loon
- Common Merganser
- Common Miner
- Common Moorhen
- Common Murre
- Common Myna
- Common Nightingale
- Common Ostrich
- Common Pheasant
- Common Pochard
- Common Quail
- Common Redshank
- Common Redstart
- Common Reed Bunting
- Common Reed Warbler
- Common Reed Warbler (baeticatus)
- Common Ringed Plover
- Common Rock Thrush
- Common Rosefinch
- Common Sandpiper
- Common Shelduck
- Common Snipe
- Common Starling
- Common Swift
- Common Tailorbird
- Common Tern
- Common Tody-Flycatcher
- Common Waxbill
- Common Whitethroat
- Common Wood Pigeon
- Common Yellowthroat
- Cooper's Hawk
- Copper Sunbird
- Coppersmith Barbet
- Cordilleran Canastero
- Corn Bunting
- Crab-plover
- Cream-colored Courser
- Cream-vented Bulbul
- Cream-winged Cinclodes
- Crescent-faced Antpitta
- Crested Ant Tanager
- Crested Barbet
- Crested Caracara (cheriway)
- Crested Duck
- Crested Francolin
- Crested Guan
- Crested Lark
- Crested Oropendola
- Crested Serpent Eagle
- Crested Tit
- Cretzschmar's Bunting
- Crimson-backed Tanager
- Crimson-breasted Shrike
- Crimson-collared Tanager
- Crimson-rumped Waxbill
- Crimson-winged Finch (alienus)
- Crimson-winged Woodpecker
- Crimson Sunbird
- Croaking Cisticola
- Croaking Ground Dove
- Crow-billed Drongo
- Crowned Cormorant
- Crowned Eagle
- Crowned Hornbill
- Crowned Lapwing
- Crowned Woodnymph
- Curlew Sandpiper
- Cut-throat Finch
- Cyprus Wheatear