- Casas de Hitos
- Caseta del Parque Guaraguao (national park)(Bayahibe)
- Caseta del Parque Guaraguao National Park (Bayahibe)
- Casiornis
- Casiornis fusca
- Casiornis fuscus
- Casiornis rufa
- Casiornis rufus
- Casmerodius albus
- Caspian Gull
- Caspian Plover
- Caspian Snowcock
- Caspian Stonechat
- Caspian Tern
- Caspian Tit
- Casqued Cacique
- Casqued Oropendola
- Cassia Crossbill
- Cassiculus
- Cassiculus melanicterus
- Cassin's Alseonax
- Cassin's Auklet
- Cassin's Finch
- Cassin's Flycatcher
- Cassin's Hawk-Eagle
- Cassin's Hawk Eagle
- Cassin's Honeybird
- Cassin's Honeyguide
- Cassin's Kingbird
- Cassin's Malimbe
- Cassin's Sparrow
- Cassin's Spinetail
- Cassin's Spinetailed Swift
- Cassin's Vireo
- Cassin's hawk-eagle
- Cassins sparrow
- Cassins vireo
- Cassin’s Malimbe
- Cassonsgrat
- Cassonsgrat(Swiss Alps)
- Cassonsgrat (Switzerland)
- Cassowaries
- Cassowary
- Castelnau's Antshrike
- Castle Eden Dene
- Castlecaldwell Forest
- Castlecaldwell Forest RSPB Reserve Northern Ireland
- Castro Marim
- Castro Marim Portugal
- Casuariidae
- Casuariiformes
- Casuarius
- Casuarius bennetti
- Casuarius casuarius
- Casuarius unappendiculatus
- Catalan Pyrenees
- Catamblyrhynchus
- Catamblyrhynchus diadema
- Catamenia
- Catamenia analis
- Catamenia homochroa
- Catamenia inornata
- Cataponera
- Cataponera turdoides
- Catbird Laughingthrush
- Caterpillar-catcher
- Catharacta
- Catharacta antarctica
- Catharacta chilensis
- Catharacta maccormicki
- Catharacta skua
- Catharacta stercorarius antarctica
- Catharopeza
- Catharopeza bishopi
- Cathartes
- Cathartes aura
- Cathartes aura aura
- Cathartes aura jota
- Cathartes burrovianus
- Cathartes burrovianus urubutinga
- Cathartes melambrotus
- Cathartidae
- Catharus
- Catharus aurantiirostris
- Catharus bicknelli
- Catharus dryas
- Catharus frantzii
- Catharus fuscater
- Catharus fuscescens
- Catharus fuscescens fuscescens
- Catharus gracilirostris
- Catharus guttatus
- Catharus maculatus
- Catharus mexicanus
- Catharus minimus
- Catharus occidentalis
- Catharus ustulatus
- Catharus ustulatus ustulatus
- Catherpes
- Catherpes mexicanus
- Catherpes mexicanus conspersus
- Catoptrophorus
- Catoptrophorus semipalmatus
- Catoptrophorus semipalmatus inornatus
- Catreus
- Catreus wallichi
- Catreus wallichii
- Cattle Egret
- Cattle Tyrant
- Cattus Island County Park
- Cattus Island County Park(Toms River)
- Catwatch
- Cauca Guan
- Caucasian Black Grouse
- Caucasian Chiffchaff
- Caucasian Great Rosefinch
- Caucasian Grouse
- Caucasian Snowcock
- Caucasus
- Caucasus Mountains
- Caura Antbird
- Cave Creek Canyon
- Cave Swallow
- Cave Swiftlet
- Cayenne Jay
- Cayenne Kite
- Cayenne Nightjar
- Cayenne Tern
- Cayman Islands
- Cayo Coco
- Cayo Guillermo
- Cayo Paredon Grande
- Cayo Romano
- Ceara Gnateater
- Ceara Woodcreeper
- Cebu Boobook
- Cebu Flowerpecker
- Cebu Hawk-Owl
- Cebu Hawk Owl
- Cecropis
- Cecropis abyssinica
- Cecropis cucullata
- Cecropis daurica
- Cecropis domicella
- Cecropis hyperythra
- Cecropis semirufa
- Cecropis senegalensis
- Cecropis striolata
- Cedar Waxwing
- Celastrina argiolus
- Celebes
- Celebes Babbler
- Celebes Barn Owl
- Celebes Bee-eater
- Celebes Blue-Flycatcher
- Celebes Blue Flycatcher
- Celebes Crested Myna
- Celebes Crow
- Celebes Drongo
- Celebes Dwarf-Hornbill
- Celebes Flycatcher
- Celebes Ground-thrush
- Celebes Ground Thrush
- Celebes Hawk-Cuckoo
- Celebes Hawk Cuckoo
- Celebes Honeyeater
- Celebes Hornbill
- Celebes King Starling
- Celebes Malia
- Celebes Mountain Drongo
- Celebes Mountain Thrush
- Celebes Mountain Whistler
- Celebes Myna
- Celebes Myzomela
- Celebes Pied Crow
- Celebes Pied Imperial Pigeon
- Celebes Rail
- Celebes Red-throated Flycatcher
- Celebes Whistler
- Celebes White-eye
- Celebes Woodswallow
- Celebes Wrinkled Hornbill
- Celebesia
- Celebesia abbotti
- Celebesia parvula
- Celery Farm(Allendale N.J.)
- Celestial Monarch
- Celeus
- Celeus brachyurus
- Celeus castaneus
- Celeus elegans
- Celeus flavescens
- Celeus flavus
- Celeus galeatus
- Celeus grammicus
- Celeus loricatus
- Celeus lugubris
- Celeus obrieni
- Celeus ochraceus
- Celeus spectabilis
- Celeus torquatus
- Celeus undatus
- Celyon Hanging-Parrot
- Centennial Park
- Centennial park(Maryland)
- Central African Republic
- Central America
- Central American Jay
- Central American Pygmy-Owl
- Central American Pygmy Owl
- Central Nicobar Serpent Eagle
- Central Park
- Central Park(New York City)
- Central Solomons Honeyeater
- Centrocercus
- Centrocercus minimus
- Centrocercus urophasianus
- Centropodidae
- Centropus
- Centropus Bengalensis
- Centropus andamanensis
- Centropus anselli
- Centropus ateralbus
- Centropus bengalensis
- Centropus bernsteini
- Centropus burchelli
- Centropus burchellii
- Centropus celebensis
- Centropus chalybeus
- Centropus chlororhynchos
- Centropus chlororhynchus
- Centropus cupreicaudus
- Centropus goliath
- Centropus grillii
- Centropus leucogaster
- Centropus melanops
- Centropus menbeki
- Centropus milo
- Centropus monachus
- Centropus neumanni
- Centropus nigrorufus
- Centropus parroti
- Centropus phasianinus
- Centropus rectunguis
- Centropus senegalensis
- Centropus sinensis
- Centropus sinensis intermedius
- Centropus sinensis parroti
- Centropus sinensis sinensis
- Centropus spilopterus
- Centropus steerii
- Centropus superciliosus
- Centropus superciliosus burchellii
- Centropus toulou
- Centropus unirufus
- Centropus violaceus
- Centropus viridis
- Centurus carolinus
- Cephalopterus
- Cephalopterus glabricollis
- Cephalopterus ornatus
- Cephalopterus penduliger
- Cephalopyrus
- Cephalopyrus flammiceps
- Cephalopyrus flammiceps olivaceus
- Cepphus
- Cepphus carbo
- Cepphus columba
- Cepphus grylle
- Cepphus grylle mandtii
- Ceram Myna
- Ceram Oriole
- Ceram Starling
- Cerasophila
- Cerasophila thompsoni
- Ceratogymna
- Ceratogymna albotibialis
- Ceratogymna atrata
- Ceratogymna brevis
- Ceratogymna bucinator
- Ceratogymna cylindrica
- Ceratogymna elata
- Ceratogymna fistulator
- Ceratogymna subcylindrica
- Ceratopipra
- Ceratopipra chloromeros
- Ceratopipra cornuta
- Ceratopipra erythrocephala
- Ceratopipra mentalis
- Ceratopipra rubrocapilla
- Cercibis
- Cercibis oxycerca
- Cercococcyx
- Cercococcyx mechowi
- Cercococcyx montanus
- Cercococcyx olivinus
- Cercomacra
- Cercomacra brasiliana
- Cercomacra carbonaria
- Cercomacra cinerascens
- Cercomacra ferdinandi
- Cercomacra fuscicauda
- Cercomacra laeta
- Cercomacra manu
- Cercomacra melanaria
- Cercomacra nigrescens
- Cercomacra nigricans
- Cercomacra parkeri
- Cercomacra serva
- Cercomacra tyrannina
- Cercomacra tyrannina tyrannina
- Cercomacroides
- Cercomacroides fuscicauda
- Cercomacroides laeta
- Cercomacroides nigrescens
- Cercomacroides parkeri
- Cercomacroides serva
- Cercomacroides tyrannina
- Cercomacroides tyrannina tyrannina
- Cercomela
- Cercomela dubia
- Cercomela familiaris
- Cercomela familiaris familiaris
- Cercomela fusca
- Cercomela fuscus
- Cercomela melanura
- Cercomela schlegelii
- Cercomela scotocerca
- Cercomela sinuata
- Cercomela sordida
- Cercomela tractrac
- Cercotrichas
- Cercotrichas barbata
- Cercotrichas coryphaeus
- Cercotrichas galactotes
- Cercotrichas galactotes galactotes
- Cercotrichas hartlaubi
- Cercotrichas leucophrys
- Cercotrichas leucosticta
- Cercotrichas minor
- Cercotrichas paena
- Cercotrichas podobe
- Cercotrichas quadrivirgata
- Cercotrichas signata
- Cereopsis


