- La Sagra's FlycatcherMyiarchus sagrae
- La Selle ThrushTurdus swalesi
- Laced WoodpeckerPicus vittatus
- Lacrimose Mountain TanagerAnisognathus lacrymosus
- Ladder-backed WoodpeckerDryobates scalaris
- Ladder-tailed NightjarHydropsalis climacocerca
- Lady Amherst's PheasantChrysolophus amherstiae
- Lafresnaye's PiculetPicumnus lafresnayi
- Lance-tailed ManakinChiroxiphia lanceolata
- Lanceolated MonkletMicromonacha lanceolata
- Lanceolated WarblerLocustella lanceolata
- Lapland LongspurCalcarius lapponicus
- Large ElaeniaElaenia spectabilis
- Large FrogmouthBatrachostomus auritus
- Large Gray BabblerArgya malcolmi
- Large Hawk-CuckooHierococcyx sparverioides
- Large NiltavaNiltava grandis
- Large Scimitar-BabblerErythrogenys hypoleucos
- Large WoodshrikeTephrodornis virgatus
- Large Wren-BabblerTurdinus macrodactylus
- Large-billed AntwrenHerpsilochmus longirostris
- Large-billed CrowCorvus macrorhynchos
- Large-billed GerygoneGerygone magnirostris
- Large-billed LarkGalerida magnirostris
- Large-billed Leaf WarblerPhylloscopus magnirostris
- Large-billed ScrubwrenSericornis magnirostra
- Large-billed Seed-FinchSporophila crassirostris
- Large-billed TernPhaetusa simplex
- Large-footed FinchPezopetes capitalis
- Large-footed TapaculoScytalopus macropus
- Large-headed FlatbillRamphotrigon megacephalum
- Large-tailed AntshrikeMackenziaena leachii
- Large-tailed DoveLeptotila megalura
- Large-tailed NightjarCaprimulgus macrurus
- Lark BuntingCalamospiza melanocorys
- Lark SparrowChondestes grammacus
- Lark-like BrushrunnerCoryphistera alaudina
- Lark-like BuntingEmberiza impetuani
- Latham's SnipeGallinago hardwickii
- Lattice-tailed TrogonTrogon clathratus
- Laughing FalconHerpetotheres cachinnans
- Laughing GullLeucophaeus atricilla
- Laughing KookaburraDacelo novaeguineae
- Lavender WaxbillGlaucestrilda caerulescens
- Lawrence's GoldfinchSpinus lawrencei
- Lawrence's ThrushTurdus lawrencii
- Layard's ParakeetPsittacula calthrapae
- Laysan AlbatrossPhoebastria immutabilis
- Lazuli BuntingPasserina amoena
- Lazuline SabrewingCampylopterus falcatus
- Leach's Storm-PetrelHydrobates leucorhous
- Leaden AntwrenMyrmotherula assimilis
- Leaden FlycatcherMyiagra rubecula
- Least AukletAethia pusilla
- Least FlycatcherEmpidonax minimus
- Least GrebeTachybaptus dominicus
- Least NighthawkChordeiles pusillus
- Least PauraqueSiphonorhis brewsteri
- Least Pygmy-OwlGlaucidium minutissimum
- Least SandpiperCalidris minutilla
- Least SeedsnipeThinocorus rumicivorus
- Least TernSternula antillarum
- LeConte's SparrowAmmospiza leconteii
- LeConte's ThrasherToxostoma lecontei
- Lemon-bellied FlyrobinMicroeca flavigaster
- Lemon-browed FlycatcherConopias cinchoneti
- Lemon-chested GreenletHylophilus thoracicus
- Lemon-rumped WarblerPhylloscopus chloronotus
- Lemon-spectacled TanagerChlorothraupis olivacea
- Lemon-throated BarbetEubucco richardsoni
- Lesser Antillean BullfinchLoxigilla noctis
- Lesser Antillean SaltatorSaltator albicollis
- Lesser Bird-of-ParadiseParadisaea minor
- Lesser Black-backed GullLarus fuscus
- Lesser Blue-eared StarlingLamprotornis chloropterus
- Lesser CoucalCentropus bengalensis
- Lesser Crested TernThalasseus bengalensis
- Lesser CuckooCuculus poliocephalus
- Lesser CuckooshrikeLalage fimbriata
- Lesser ElaeniaElaenia chiriquensis
- Lesser FlamingoPhoeniconaias minor
- Lesser GoldfinchSpinus psaltria
- Lesser Grass-FinchEmberizoides ypiranganus
- Lesser Gray ShrikeLanius minor
- Lesser Green LeafbirdChloropsis cyanopogon
- Lesser GreenletPachysylvia decurtata
- Lesser Ground-CuckooMorococcyx erythropygus
- Lesser Ground-RobinAmalocichla incerta
- Lesser HoneyguideIndicator minor
- Lesser HorneroFurnarius minor
- Lesser KestrelFalco naumanni
- Lesser Masked-WeaverPloceus intermedius
- Lesser MelampittaMelampitta lugubris
- Lesser Necklaced LaughingthrushGarrulax monileger
- Lesser NighthawkChordeiles acutipennis
- Lesser NoddyAnous tenuirostris
- Lesser Prairie-ChickenTympanuchus pallidicinctus
- Lesser Racket-tailed DrongoDicrurus remifer
- Lesser RoadrunnerGeococcyx velox
- Lesser ScaupAythya affinis
- Lesser ShortwingBrachypteryx leucophris
- Lesser Spotted EagleClanga pomarina
- Lesser Spotted WoodpeckerDryobates minor
- Lesser Striped SwallowCecropis abyssinica
- Lesser Swamp WarblerAcrocephalus gracilirostris
- Lesser Vasa ParrotCoracopsis nigra
- Lesser VioletearColibri cyanotus
- Lesser Wagtail-TyrantStigmatura napensis
- Lesser Whistling-DuckDendrocygna javanica
- Lesser White-fronted GooseAnser erythropus
- Lesser WhitethroatCurruca curruca
- Lesser WoodcreeperXiphorhynchus fuscus
- Lesser YellowlegsTringa flavipes
- Lesser YellownapePicus chlorolophus
- Lesson's MotmotMomotus lessonii
- Lesson's SeedeaterSporophila bouvronides
- Lettered AracariPteroglossus inscriptus
- Levaillant's CisticolaCisticola tinniens
- Levaillant's CuckooClamator levaillantii
- Levaillant's WoodpeckerPicus vaillantii
- Lewin's HoneyeaterMeliphaga lewinii
- Lewin's RailLewinia pectoralis
- Lewis's WoodpeckerMelanerpes lewis
- Leymebamba AntpittaGrallaricula leymebambae
- Lidth's JayGarrulus lidthi
- Light-crowned SpinetailCranioleuca albiceps
- Light-vented BulbulPycnonotus sinensis
- Lilac-breasted RollerCoracias caudatus
- Lilac-crowned AmazonAmazona finschi
- Lilac-tailed ParrotletTouit batavicus
- Limestone Leaf WarblerPhylloscopus calciatilis
- LimpkinAramus guarauna
- Lincoln's SparrowMelospiza lincolnii
- Line-cheeked SpinetailCranioleuca antisiensis
- Line-fronted CanasteroAsthenes urubambensis
- Lineated BarbetPsilopogon lineatus
- Lineated Foliage-gleanerSyndactyla subalaris
- Lineated WoodpeckerDryocopus lineatus
- Lined AntshrikeThamnophilus tenuepunctatus
- Lined Forest-FalconMicrastur gilvicollis
- Lined Quail-DoveZentrygon linearis
- Lined SeedeaterSporophila lineola
- Little Bee-eaterMerops pusillus
- Little Blue HeronEgretta caerulea
- Little BuntingEmberiza pusilla
- Little BustardTetrax tetrax
- Little CorellaCacatua sanguinea
- Little CormorantMicrocarbo niger
- Little CrakeZapornia parva
- Little CuckooCoccycua minuta
- Little Cuckoo-DoveMacropygia ruficeps
- Little CurlewNumenius minutus
- Little EgretEgretta garzetta
- Little FriarbirdPhilemon citreogularis
- Little GrassbirdPoodytes gramineus
- Little GrebeTachybaptus ruficollis
- Little Green-PigeonTreron olax
- Little GreenbulEurillas virens
- Little GullHydrocoloeus minutus
- Little HermitPhaethornis longuemareus
- Little NightjarSetopagis parvula
- Little OwlAthene noctua
- Little PenguinEudyptula minor
- Little Pied FlycatcherFicedula westermanni
- Little RavenCorvus mellori
- Little Rush WarblerBradypterus baboecala
- Little ShrikethrushColluricincla megarhyncha
- Little Slaty FlycatcherFicedula basilanica
- Little SpiderhunterArachnothera longirostra
- Little StintCalidris minuta
- Little SwiftApus affinis
- Little TernSternula albifrons
- Little ThornbirdPhacellodomus sibilatrix
- Little TinamouCrypturellus soui
- Little WattlebirdAnthochaera chrysoptera
- Little WeaverPloceus luteolus
- Little WoodpeckerDryobates passerinus
- Livingstone's TuracoTauraco livingstonii
- Lizard BuzzardKaupifalco monogrammicus
- Loggerhead KingbirdTyrannus caudifasciatus
- Loggerhead ShrikeLanius ludovicianus
- Loja TapaculoScytalopus androstictus
- Lompobattang Leaf WarblerPhylloscopus sarasinorum
- Long-billed BernieriaBernieria madagascariensis
- Long-billed CorellaCacatua tenuirostris
- Long-billed CrombecSylvietta rufescens
- Long-billed CrowCorvus validus
- Long-billed CurlewNumenius americanus
- Long-billed DowitcherLimnodromus scolopaceus
- Long-billed GnatwrenRamphocaenus melanurus
- Long-billed HermitPhaethornis longirostris
- Long-billed PipitAnthus similis
- Long-billed StarthroatHeliomaster longirostris
- Long-billed TailorbirdArtisornis moreaui
- Long-billed ThrasherToxostoma longirostre
- Long-billed WoodcreeperNasica longirostris
- Long-billed WrenCantorchilus longirostris
- Long-billed Wren-BabblerNapothera malacoptila
- Long-crested EagleLophaetus occipitalis
- Long-crested Pygmy-TyrantLophotriccus eulophotes
- Long-eared OwlAsio otus
- Long-tailed BroadbillPsarisomus dalhousiae
- Long-tailed Bush WarblerLocustella caudata
- Long-tailed CinclodesCinclodes pabsti
- Long-tailed DuckClangula hyemalis
- Long-tailed FiscalLanius cabanisi
- Long-tailed Glossy StarlingLamprotornis caudatus
- Long-tailed HawkUrotriorchis macrourus
- Long-tailed HermitPhaethornis superciliosus
- Long-tailed JaegerStercorarius longicaudus
- Long-tailed KoelUrodynamis taitensis
- Long-tailed ManakinChiroxiphia linearis
- Long-tailed MeadowlarkLeistes loyca
- Long-tailed MinivetPericrocotus ethologus
- Long-tailed MockingbirdMimus longicaudatus
- Long-tailed MynaMino kreffti
- Long-tailed NightjarCaprimulgus climacurus
- Long-tailed ParakeetPsittacula longicauda
- Long-tailed PotooNyctibius aethereus
- Long-tailed Reed FinchDonacospiza albifrons
- Long-tailed RosefinchCarpodacus sibiricus
- Long-tailed ShrikeLanius schach
- Long-tailed SibiaHeterophasia picaoides
- Long-tailed Silky-flycatcherPtiliogonys caudatus
- Long-tailed SylphAglaiocercus kingii
- Long-tailed TapaculoScytalopus micropterus
- Long-tailed TitAegithalos caudatus
- Long-tailed TrillerLalage leucopyga
- Long-tailed TyrantColonia colonus
- Long-tailed WidowbirdEuplectes progne
- Long-tailed Wood-PartridgeDendrortyx macroura
- Long-toed StintCalidris subminuta
- Long-tufted Screech-OwlMegascops sanctaecatarinae
- Long-wattled UmbrellabirdCephalopterus penduliger
- Long-whiskered OwletXenoglaux loweryi
- Long-winged AntwrenMyrmotherula longipennis
- Long-winged HarrierCircus buffoni
- Loten's SunbirdCinnyris lotenius
- Louisiana WaterthrushParkesia motacilla
- Lovely FairywrenMalurus amabilis
- Lowland White-eyeZosterops meyeni
- Lucifer HummingbirdCalothorax lucifer
- Lucy's WarblerLeiothlypis luciae
- Lühder's BushshrikeLaniarius luehderi
- Lunulated AntbirdOneillornis lunulatus
- Luzon BoobookNinox philippensis
- Lyre-tailed NightjarUropsalis lyra