- Common Eider
- Common Emerald Dove
- Common Fairy-Tern
- Common Firecrest
- Common Fiscal
- Common Flame-backed Woodpecker
- Common Flameback
- Common Fulvetta
- Common Gallinule
- Common Golden Whistler
- Common Goldenback
- Common Goldenback Woodpecker
- Common Goldeneye
- Common Gonolek
- Common Grackle
- Common Grasshopper-Warbler
- Common Grasshopper Warbler
- Common Gray Hornbill
- Common Green-Magpie
- Common Green Magpie
- Common Greenshank
- Common Grenadier
- Common Grey-headed Sparrow
- Common Grey Hornbill
- Common Ground-Dove
- Common Ground Dove
- Common Guillemot
- Common Gull
- Common Hawk-Cuckoo
- Common Hawk Cuckoo
- Common Hill Myna
- Common Hill Mynah
- Common Hoopoe
- Common House-Martin
- Common House Martin
- Common Iora
- Common Jackdaw
- Common Jay
- Common Jery
- Common Jezebel
- Common Jezebel Butterfly
- Common Kestrel
- Common King Crow
- Common Kingfisher
- Common Kiwi
- Common Koel
- Common Linnet
- Common Lizard Cuckoo
- Common Loon
- Common Magpie
- Common Merganser
- Common Miner
- Common Moorhen
- Common Mormon Butterfly
- Common Murre
- Common Myna
- Common Mynah
- Common Newtonia
- Common Nighthawk
- Common Nightingale
- Common Noddy-Tern
- Common Ostrich
- Common Paradise-Kingfisher
- Common Paradise Kingfisher
- Common Pauraque
- Common Peafowl
- Common Pheasant
- Common Pigeon
- Common Pochard
- Common Poorwill
- Common Potoo
- Common Quail
- Common Raven
- Common Redpoll
- Common Redshank
- Common Redstart
- Common Reed Bunting
- Common Ringed Plover
- Common Rock-Sparrow
- Common Rock Sparrow
- Common Rock Thrush
- Common Rosefinch
- Common Rouge-et-noir Bird
- Common Sandpiper
- Common Scale-backed Antbird
- Common Scimitar-bill
- Common Scimitarbill
- Common Scops-Owl
- Common Scops Owl
- Common Scoter
- Common Shag
- Common Shelduck
- Common Slender-billed Weaver
- Common Smoky Honeyeater
- Common Snipe
- Common Snowfinch
- Common Square-tailed Drongo
- Common Starling
- Common Stonechat
- Common Sunbird-Asity
- Common Swift
- Common Tailorbird
- Common Tanager Finch
- Common Teal
- Common Tern
- Common Thornbird
- Common Tiger
- Common Tiger Butterfly
- Common Tody-Flycatcher
- Common Tody Flycatcher
- Common Treecreeper
- Common Waxbill
- Common White Tern
- Common Whitethroat
- Common Wood-Pigeon
- Common Wood-Shrike
- Common Wood-shrike
- Common Wood Pigeon
- Common Woodpigeon
- Common Woodshrike
- Common Wren
- Common Yellowthroat
- Common ground-Dove
- Common mynah
- Common or Grey Potoo
- Common sunbird asity
- Comoro Blue-Pigeon
- Comoro Blue Pigeon
- Comoro Blue Vanga
- Comoro Bulbul
- Comoro Drongo
- Comoro Islands
- Comoro Olive-Pigeon
- Comoro Olive Pigeon
- Comoro Pigeon
- Comoro Scops-Owl
- Comoro Scops Owl
- Comoro Thrush
- Comoro Tsikirity
- Comoro Vanga
- Comoro White-eye
- Comoros
- Comoros Blue Pigeon
- Comoros Bulbul
- Comoros Cuckoo-shrike
- Comoros Cuckooshrike
- Comoros Fody
- Comoros Green-Pigeon
- Comoros Green Pigeon
- Comoros Islands
- Comoros Thrush
- Compact Weaver
- Compsospiza
- Compsospiza baeri
- Compsospiza garleppi
- Compsothraupis
- Compsothraupis loricata
- Concave-casqued Hornbill
- Condor
- Condors
- Cone-billed Tanager
- Congo
- Congo (Brazzaville)
- Congo (Kinshasa)
- Congo Bay-Owl
- Congo Bay Owl
- Congo Greenbul
- Congo Martin
- Congo Moor-Chat
- Congo Moor Chat
- Congo Moorchat
- Congo Peacock
- Congo Peafowl
- Congo Serpent-Eagle
- Congo Serpent Eagle
- Congo Sunbird
- Congo Swift
- Conguillio National Park
- Conguillio National Park(9th Region)
- Conioptilon
- Conioptilon mcilhennyi
- Conirostrum
- Conirostrum albifrons
- Conirostrum bicolor
- Conirostrum bicolor bicolor
- Conirostrum cinereum
- Conirostrum ferrugineiventre
- Conirostrum leucogenys
- Conirostrum margaritae
- Conirostrum rufum
- Conirostrum sitticolor
- Conirostrum speciosum
- Conirostrum tamarugense
- Connecticut
- Connecticut Warbler
- Connemara National Park
- Conopias
- Conopias albovittata
- Conopias albovittatus
- Conopias cinchoneti
- Conopias cinchoneti icterophrys
- Conopias parva
- Conopias parvus
- Conopias trivirgata
- Conopias trivirgatus
- Conopophaga
- Conopophaga ardesiaca
- Conopophaga aurita
- Conopophaga castaneiceps
- Conopophaga cearae
- Conopophaga lineata
- Conopophaga melanogaster
- Conopophaga melanops
- Conopophaga peruviana
- Conopophaga roberti
- Conopophagidae
- Conopophila
- Conopophila albogularis
- Conopophila rufogularis
- Conopophila whitei
- Conostoma
- Conostoma aemodium
- Conostoma oemodium
- Conothraupis
- Conothraupis mesoleuca
- Conothraupis speculigera
- Contopus
- Contopus albogularis
- Contopus caribaeus
- Contopus cinereus
- Contopus cooperi
- Contopus fumigatus
- Contopus hispaniolensis
- Contopus latirostris
- Contopus lugubris
- Contopus nigrescens
- Contopus ochraceus
- Contopus pallidus
- Contopus pertinax
- Contopus punensis
- Contopus sordidulus
- Contopus virens
- Conuropsis
- Conuropsis carolinensis
- Conwy
- Cook
- Cook's Azure-winged Magpie
- Cook's Petrel
- Cook's Swift
- Cook Islands
- Cook Islands Fruit-Dove
- Cook Islands Fruit Dove
- Cook Islands Monarch
- Cook Islands Reed-Warbler
- Cook Islands Reed Warbler
- Cook Islands Swiftlet
- Cook Reed Warbler
- Cook Swiftlet
- Coolpix 4500
- Coolpix 5700
- Coolpix 990
- Coombe Hill Nature Reserve
- Coombe Valley RSPB Reserve
- Coombes and Churnet
- Cooper's Hawk
- Coopmans's Elaenia
- Coopmans's Tyrannulet
- Coorong
- Coot
- Coots
- Cop Mere
- Copenhagen Area Denmark
- Copenhagen area
- Copinsay
- Copinsay Orkney Islands
- Copinsay RSPB Reserve Orkney Islands, Scotland
- Copper-rumped Hummingbird
- Copper-tailed Glossy-Starling
- Copper-tailed Glossy Starling
- Copper-tailed Hummingbird
- Copper-tailed Starling
- Copper-throated Sunbird
- Copper Pheasant
- Copper Seedeater
- Copper Sunbird
- Copperback
- Copperback Quail-thrush
- Coppersmith Barbet
- Coppery-bellied Puffleg
- Coppery-chested Jacamar
- Coppery-headed Emerald
- Coppery-naped Puffleg
- Coppery-tailed Coucal
- Coppery-tailed Starling
- Coppery-tailed Trogon
- Coppery Emerald
- Coppery Metaltail
- Coppery Thorntail
- Copsychus
- Copsychus Saularis
- Copsychus albiventris
- Copsychus albospecularis
- Copsychus cebuensis
- Copsychus fulicatus
- Copsychus luzoniensis
- Copsychus malabaricus
- Copsychus malabaricus macrourus
- Copsychus mindanensis
- Copsychus niger
- Copsychus pyrropygus
- Copsychus saularis
- Copsychus saularis prosthopellus
- Copsychus sechellarum
- Copsychus stricklandi
- Copsychus stricklandii
- Copsychus superciliaris
- Coquerel's Coua
- Coquerel's Madagascar Coucal
- Coquet Island and Amble
- Coqui Francolin
- Coracias
- Coracias Cyanogaster
- Coracias abyssinica
- Coracias abyssinicus
- Coracias benghalensis
- Coracias benghalensis indicus
- Coracias caudata
- Coracias caudatus
- Coracias caudatus lorti
- Coracias cyanogaster
- Coracias garrulus
- Coracias garrulus semenowi
- Coracias naevia
- Coracias naevius
- Coracias noevius
- Coracias spatulata
- Coracias spatulatus
- Coracias temminckii
- Coraciidae
- Coraciiformes
- Coracina
- Coracina abbotti
- Coracina analis
- Coracina atriceps
- Coracina azurea


