| Common Name | Scientific name |
|---|---|
| Cinnamon-bellied Flowerpiercer | Diglossa baritula |
| Cinnamon-tailed Sparrow | Peucaea sumichrasti |
| Cirl Bunting | Emberiza cirlus |
| Citreoline Trogon | Trogon citreolus |
| Citril Finch | Carduelis citrinella |
| Citrine Wagtail | Motacilla citreola |
| Clapper Rail | Rallus crepitans |
| Clarion Wren | Troglodytes tanneri |
| Clark's Grebe | Aechmophorus clarkii |
| Clark's Nutcracker | Nucifraga columbiana |
| Clay-colored Sparrow | Spizella pallida |
| Clay-colored Thrush | Turdus grayi |
| Cliff Swallow | Petrochelidon pyrrhonota |
| Coal Tit | Periparus ater |
| Cockatiel | Nymphicus hollandicus |
| Cocoa Thrush | Turdus fumigatus |
| Cocoa Woodcreeper | Xiphorhynchus susurrans |
| Cocoi Heron | Ardea cocoi |
| Cocos Cuckoo | Coccyzus ferrugineus |
| Cocos Finch | Pinaroloxias inornata |
| Cocos Flycatcher | Nesotriccus ridgwayi |
| Coiba Spinetail | Cranioleuca dissita |
| Colima Pygmy-Owl | Glaucidium palmarum |
| Colima Warbler | Oreothlypis crissalis |
| Collared Aracari | Pteroglossus torquatus |
RingBase adheres to EURING codes.
