Here's a list of birds I identified in Costa Rica:
Great Tinamou Tinamus major
Little Tinamou Crypturellus soui
Black-bellied Whistling-Duck Dendrocygna autumnalis
Blue-winged Teal Anas discors
Northern Shoveler Anas clypeata
Crested Guan Penelope purpurascens
Black-breasted Wood-Quail Odontophorus leucolaemus
Least Grebe Tachybaptus dominicus
Pied-billed Grebe Podilymbus podiceps
Brown Pelican Pelecanus occidentalis
Neotropic Cormorant Phalacrocorax brasilianus
Anhinga Anhinga anhinga
Magnificent Frigatebird Fregata magnificens
Yellow-crowned Night-Heron Nyctanassa violacea
Green Heron Butorides virescens
Cattle Egret Bubulcus ibis
Great Blue Heron Ardea herodias
Great Egret Ardea alba
Snowy Egret Egretta thula
Little Blue Heron Egretta caerulea
White Ibis Eudocimus albus
Jabiru Jabiru mycteria
Wood Stork Mycteria americana
Black Vulture Coragyps atratus
Turkey Vulture Cathartes aura
King Vulture Sarcoramphus papa
Osprey Pandion haliaeus
Gray-headed Kite Leptodon cayanensis
Hook-billed Kite Chondroheirax uncinatus
Swallow-tailed Kite Elanoides forficatus:
White-tailed Kite Elanus leucurus
Snail Kite Rostrhamus sociabilis
Double-toothed Kite Harpagus bidentatus:
Mississippi Kite Ictinia mississippiensis:
Plumbeous Kite Ictinia plumbea
Northern Harrier Circus cyaneus
Sharp-shinned Hawk Accipiter striatus
Cooper's Hawk Accipiter cooperii
White Hawk Leucopternis albicollis
Gray Hawk Asturina nitida
Common Black-Hawk Buteogallus anthracinus
Roadside Hawk Buteo magnirostris
Broad-winged Hawk Buteo platypterus:
Short-tailed Hawk Buteo brachyurus
Swainson's Hawk Buteo swainsoni:
Zone-tailed Hawk Buteo albononatus
Red-tailed Hawk Buteo jamaicensis
Black Hawk-Eagle Spizaetus tyrannus
Crested Caracara Caracara cheriway
Yellow-headed Caracara Milvago chimachima
Laughing Falcon Herpetotheres cachinnans
Slaty-backed Forest-Falcon Micrastur mirandollei
American Kestrel Falco sparverius
Bat Falcon Falco rufigularis
Merlin Falco columbarius
Peregrine Falcon Falco peregrinus
Gray-necked Wood-Rail Aramides cajanea
Common Moorhen Gallinula chloropus
Purple Gallinule Porphyrio martinica
American Coot Fulica americana
Sunbittern Eurypyga helias
Black-bellied Plover Pluvialis squatarola
Wilson's Plover Charadrius wilsonia
Semipalmated Plover Charadrius semipalmatus
Killdeer Charadrius vociferus
American Oystercatcher Haematopus palliatus
Northern Jacana Jacana spinosa
Lesser Yellowlegs Tringa flavipes
Solitary Sandpiper Tringa solitaria
Spotted Sandpiper Actitis macularius
Whimbrel Numenius phaeopus
Sanderling Calidris alba
Western Sandpiper Calidris mauri
Common Snipe Gallinago gallinago
Royal Tern Sterna maxima
Rock Dove Columba livia
Scaled Pigeon Patagioenas speciosa
Red-billed Pigeon Patagioenas flavirostris
Band-tailed Pigeon Patagioenas fasciata
Ruddy Pigeon Patagioenas subvinacea
Short-billed Pigeon Patagioenas nigrirostris
White-winged Dove Zenaida asiatica
Inca Dove Columbina inca
Ruddy Ground-Dove Columbina talpacoti
Ruddy Quail-Dove Geotrygon montana
Sulfur-winged Parakeet Pyrrhura hoffmanni
Crimson-fronted Parakeet Aratinga finschi
Olive-throated Parakeet Aratinga nana
Scarlet Macaw Ara macao
Brown-hooded Parrot Pionopsitta haematotis
Blue-headed Parrot Pionus menstruus
White-crowned Parrot Pionus senilis
White-fronted Parrot Amazona albifrons
Red-lored Parrot Amazona autumnalis
Mealy Parrot Amazona farinosa
Yellow-billed Cuckoo Coccyzus americanus
Squirrel Cuckoo Piaya cayana
Groove-billed Ani Crotophaga sulcirostris
Black-and-white Owl Ciccaba nigrolineata
Common Pauraque Nyctidromus albicollis
Black Swift Cypseloides niger
White-collared Swift Streptoprocne zonaris
Chimney Swift Chaetura pelagica
Lesser Swallow-tailed Swift Panyptila cayennensis
Bronzy Hermit Glaucis aeneus
Green Hermit Phaethornis guy
Long-billed Hermit Phaethornis longirostris
Stripe-throated Hermit Phaethornis striigularis
Violet Sabrewing Campylopterus hemileucurus
White-necked Jacobin Florisuga mellivora
Brown Violet-Ear Colibri delphinae
Green Violet-ear Colibri thalassinus
Green Thorntail Discosura conversii
Crowned Woodnymph Thalurania colombica
Blue-throated Goldentail Hylocharis eliciae
Blue-chested Hummingbird Amazilia amabilis
Snowy-bellied Hummingbird Amazilia edward
Rufous-tailed Hummingbird Amazilia tzacatl
Black-bellied Hummingbird Eupherusa nigriventris
Coppery-headed Emerald Elvira cupreiceps
Bronze-tailed Plumeleteer Chalybura urochrysia
White-bellied Mountain-gem Lampornis hemileucus
Purple-throated Mountain-gem Lampornis calolaemus
Gray-tailed Mountain-gem Lampornis cinereicauda
Green-Crowned Brilliant Heliodoxa jacula
Magnificent Hummingbird Eugenes fulgens
Purple-crowned Fairy Heliothryx barroti
Magenta-throated Woodstar Calliphlox bryantae
Ruby-throated Hummingbird Archilochus colubris
Volcano Hummingbird Selasphorus flammula
Scintillant Hummingbird Selasphorus scintilla
Violaceous Trogon Trogon violaceus
Collared Trogon Trogon collaris
Orange-bellied Trogon Trogon aurantiiventris
Black-throated Trogon Trogon rufus
Slaty-tailed Trogon Trogon massena
Resplendent Quetzal Pharomachrus mocinno
Blue-crowned Motmot Momotus momota
Ringed Kingfisher Ceryle torquatus
Belted Kingfisher Ceryle alcyon
Green Kingfisher Chloroceryle americana
Pied Puffbird Notharchus tectus
White-wiskered Puffbird Malacoptila panamensis
Great Jacamar Jacamerops aureus
Red-headed Barbet Eubucco bourcierii
Prong-billed Barbet Semnornis frantzii
Emerald Toucanet Aulacorhynchus prasinus
Collared Aracari Pteroglossus torquatus
Keel-billed Toucan Ramphastos sulfuratus
Chestnut-mandibled Toucan Ramphastos swainsonii:
Acorn Woodpecker Melanerpes formicivorus
Black-cheeked Woodpecker Melanerpes pucherani
Hoffmann's Woodpecker Melanerpes hoffmannii
Yellow-bellied Sapsucker Sphyrapicus varius
Golden-olive Woodpecker Piculus rubiginosus
Pale-billed Woodpecker Campephilus guatamalensis
Red-faced Spinetail Cranioleuca erythrops
Buffy Tuftedcheek Pseudocolaptes lawrencii
Plain Xenops Xenops minutus
Wedge-billed Woodcreeper Glyphorhynchus spirurus
Northern Barred Woodcreeper Dendrocolaptes sanctithomae
Cocoa Woodcreeper Xiphorhynchus susurrans
Streak-headed Woodcreeper Lepidocolaptes souleyetii
Barred Antshrike Thamnophilus doliatus
Western Slaty Antshrike Thamnophilus atrinucha
Checker-throated Antwren Myrmotherula fulviventris
Dot-winged Antwren Microrhopias quixensis
Chestnut-backed Antbird Myrmeciza exsul
Bicolored Antbird Gymnopithys leucaspis
Yellow-bellied Elaenia Elaenia flavogaster
Olive-striped Flycatcher Mionectes olivaceus
Paltry Tyrannulet Zimmerius vilissimus
Scale-crested Pygmy-Tyrant Lophotriccus pileatus
Common Tody-Flycatcher Todirostrum cinereum
Black-headed Tody-Flycatcher Todirostrum nigriceps
Eye-ringed Flatbill Rhynchocyclus brevirostris
Western Wood-Pewee Contopus sordidulus
Eastern Wood-Pewee Contopus virens
Black-capped Flycatcher Empidonax atriceps
Black Phoebe Sayornis nigricans
Long-tailed Tyrant Colonia colonus
Dusky-capped Flycatcher Myiarchus tuberculifer
Great Crested Flycatcher Myiarchus crinitus
Great Kiskadee Pitangus sulphuratus
Boat-billed Flycatcher Megarhynchus pitangua
Gray-capped Flycatcher Myiozetetes granadensis
White-ringed Flycatcher Conopias albovittatus
Golden-bellied Flycatcher Myiodynastes hemichrysus
Sulphur-bellied Flycatcher Myiodynastes luteiventris
Eastern Kingbird Tyrannus tyrannus
Scissor-tailed Flycatcher Tyrannus forficatus
Cinnamon Becard Pachyramphus cinnamomeus
Masked Tityra Tityra semifasciata
Black-crowned Tityra Tityra inquisitor
Snowy Cotinga Carpodectes nitidus
Purple-throated Fruitcrow Querula purpurata
White-collared Manakin Manacus candei
Long-tailed Manakin Chiroxiphia linearis
Red-capped Manakin Pipra mentalis
Yellow-throated Vireo Vireo flavifrons
Philadelphia Vireo Vireo philadelphicus
Red-eyed Vireo Vireo olicaceus
Lesser Greenlet Hylophilus decurtatus
White-throated Magpie-Jay Calocitta formosa
Brown Jay Cyanocorax morio
Silvery-throated Jay Cyanolyca argentigula
Purple Martin Progne subis
Blue-and-white Swallow Pygochelidon cyanoleuca
Northern Rough-winged Swallow Stelgidopteryx serripennis
Southern Rough-winged Swallow Stelgidopteryx ruficollis
Cliff Swallow Petrochelidon pyrrhonota
Barn Swallow Hirundo rustica
Rufous-naped Wren Campylorhynchus rufinucha
Bay Wren Thryothorus nigricapillus
Riverside Wren Thryothorus semibadius
Stripe-breasted Wren Thryothorus thoracicus
Banded Wren Thryothorus pleurostictus
Plain Wren Thryothorus modestus
House Wren Troglodytes aedon
Ochraceous Wren Troglodytes ochraceus
White-breasted Wood-Wren Henicorhina leucosticta
Gray-breasted Wood-Wren Henicorhina leucophrys
Scaly-breasted Wren Microcerculus marginatus
Song Wren Cyphorhinus phaeocephalus
American Dipper Cinclus mexicanus
Tawny-faced Gnatwren Microbates cinereiventris
Long-billed Gratwren Ramphocaenus melanurus
Tropical Gnatcatcher Polioptila plumbea
Black-faced Solitaire Myadestes melanops
Orange-billed Nightingale-Thrush Catharus aurantiirostris
Slaty-backed Nightingale-Thrush Catharus fuscater
Swainson's Thrush Catharus ustulatus
Wood Thrush Hylocichla mustelina
Clay-colored Robin Turdus grayi
Golden-winged Warbler Vermivora chrysoptera
Tennessee Warbler Vermivora peregrina
Northern Parula Parula americana
Tropical Parula Parula pitiayumi
Chestnut-sided Warbler Dendroica pensylvanica
Magnolia Warbler Dendroica magnolia
Yellow-rumped Warbler Dendroica coronata
Black-throated Green Warbler Dendroica virens
Blackburnian Warbler Dendroica fusca
Bay-breasted Warbler Dendroica castanea
Black-and-white Warbler Mniotilta varia
American Redstart Setophaga ruticilla
Northern Waterthrush Seiurus noveboracensis
Mourning Warbler Oporornis philadelphia
Olive-crowned Yellowthroat Geothlypis semiflava
Gray-crowned Yellowthroat Geothlypis poliocephala
Wilson's Warbler Wilsonia pusilla
Canada Warbler Wilsonia canadensis
Slate-throated Redstart Myioborus miniatus
Collared Redstart Myioborus torquatus
Rufous-capped Warbler Basileuterus rufifrons
Black-cheeked Warbler Basileuterus melanogenys
Buff-rumped Warbler Phaeothlypis fulvicauda
Bananaquit Coereba flaveola
Common Bush-Tanager Chlorospingus opthalmicus
Sooty-capped Bush-Tanager Chlorospingus pileatus
White-shouldered Tanager Tachyphonus luctousus
Tawny-crested Tanager Tachyphonus delattrii
White-lined Tanager Tachyphonus rufus
Red-crowned Ant-Tanager Habia rubica
Red-throated Ant-Tanager Habia fuscicauda
Summer Tanager Piranga rubra
Scarlet Tanager Piranga olivacea
Western Tanager Piranga ludoviciana
Flame-colored Tanager Piranga bidentata
White-winged Tanger Piranga leucoptera
Crimson-collared Tanager Ramphocelus sanguinolentus
Passerini's Tanager Ramphocelus passerinii
Blue-gray Tanager Thraupis episcopus
Palm Tanager Thraupis palmarum
Plain-colored Tanager Tangara inornata
Emerald Tanager Tangara florida
Silver-throated Tanager Tangara icterocephala
Speckled Tanager Tangara guttata
Bay-headed Tanager Tangara gyrola
Rufous-winged Tanager Tangara lavinia
Golden-hooded Tanager Tangara larvata
Spangle-cheeked Tanager Tangara dowii
Scarlet-thighed Dacnis Dacnis venusta
Blue Dacnis Dacnis cayana
Green Honeycreeper Chlorophanes spiza
Shining Honeycreeper Cyanerpes lucidus
Variable Seedeater Sporophila americana
White-collared Seedeater Sporophila torqueola
Yellow-faced Grassquit Tiaris olivaceus
Slaty Flowerpiercer Diglossa plumbea
Yellow-thighed Finch Pselliophorus tibialis
Large-footed Finch Pezopetes capitalis
Black-striped Sparrow Arremonops conirostris
White-eared Ground-Sparrow Melozone leucotis
Stripe-headed Sparrow Aimophila ruficauda
Rufous-collared Sparrow Zonotrichia capensis
Volcano Junco Junco vulcani
Grayish Saltator Saltator coerulescens
Buff-throated Saltator Saltator maximus
Black-headed Saltator Saltator atriceps
Slate-colored Grosbeak Saltator grossus
Rose-breasted Grosbeak Pheucticus ludovicianus
Black-headed Grosbeak Pheucticus melanocephalus
Blue-black Grosbeak Cyanocompsa cyanoides
Red-winged Blackbird Agelaius phoniceus
Great-tailed Grackle Quiscalus mexicanus
Bronzed Cowbird Molothrus aeneus
Baltimore Oriole Icterus galbula
Scarlet-rumped Cacique Cacicus uropygialis
Chestnut-headed Oropendola Psarocolius wagleri
Montezuma Oropendola Psarocolius montezuma
Yellow-throated Euphonia Euphonia hirundinacea
Olive-backed Euphonia Euphonia gouldi
White-vented Euphonia Euphonia minuta
Tawny-capped Euphonia Euphonia anneae
Lesser Goldfinch Carduelis psaltria
House Sparrow Passer domesticus