- Megascops asio
- Megascops atricapilla
- Megascops atricapillus
- Megascops barbarus
- Megascops centralis
- Megascops choliba
- Megascops choliba crucigerus
- Megascops clarkii
- Megascops colombianus
- Megascops cooperi
- Megascops flammeolus
- Megascops guatemalae
- Megascops hoyi
- Megascops ingens
- Megascops kennicottii
- Megascops koepckeae
- Megascops lambi
- Megascops marshalli
- Megascops napensis
- Megascops nudipes
- Megascops pacificus
- Megascops petersoni
- Megascops roboratus
- Megascops roraimae
- Megascops sanctaecatarinae
- Megascops seductus
- Megascops trichopsis
- Megascops usta
- Megascops vermiculatus
- Megascops vermiculatus centralis
- Megascops watsonii
- Megastictus
- Megastictus margaritatus
- Megatriorchis
- Megatriorchis doriae
- Megaxenops
- Megaxenops parnaguae
- Megazosterops
- Megazosterops palauensis
- Meiglyptes
- Meiglyptes jugularis
- Meiglyptes tristis
- Meiglyptes tukki
- Meikle Loch
- Meinertzhagen's Snowfinch
- Mekong Wagtail
- Melaenornis
- Melaenornis annamarulae
- Melaenornis ardesiacus
- Melaenornis brunneus
- Melaenornis chocolatinus
- Melaenornis edolioides
- Melaenornis fischeri
- Melaenornis fischeri toruensis
- Melaenornis herero
- Melaenornis infuscatus
- Melaenornis mariquensis
- Melaenornis microrhynchus
- Melaenornis pallidus
- Melaenornis pammelaina
- Melaenornis semipartitus
- Melaenornis silens
- Melampitta
- Melampitta gigantea
- Melampitta lugubris
- Melampittidae
- Melamprosops
- Melamprosops phaeosoma
- Melancholy Woodpecker
- Melanerpes
- Melanerpes aurifrons
- Melanerpes cactorum
- Melanerpes candidus
- Melanerpes carolinus
- Melanerpes chrysauchen
- Melanerpes chrysogenys
- Melanerpes cruentatus
- Melanerpes erythrocephalus
- Melanerpes flavifrons
- Melanerpes formicivorus
- Melanerpes herminieri
- Melanerpes hoffmannii
- Melanerpes hypopolius
- Melanerpes lewis
- Melanerpes portoricensis
- Melanerpes pucherani
- Melanerpes pulcher
- Melanerpes pygmaeus
- Melanerpes radiolatus
- Melanerpes rubricapillus
- Melanerpes santacruzi
- Melanerpes striatus
- Melanerpes superciliaris
- Melanerpes superciliaris superciliaris
- Melanerpes uropygialis
- Melanerpes uropygialis cardonensis
- Melanesia
- Melanesian Cuckoo-Shrike
- Melanesian Cuckoo-shrike
- Melanesian Cuckooshrike
- Melanesian Flycatcher
- Melanesian Kingfisher
- Melanesian Megapode
- Melanesian Myiagra
- Melanesian Scrubfowl
- Melanesian Thicketbird
- Melanesian Whistler
- Melanic Honeyeater
- Melaniparus
- Melaniparus afer
- Melaniparus albiventris
- Melaniparus carpi
- Melaniparus cinerascens
- Melaniparus fasciiventer
- Melaniparus fringillinus
- Melaniparus funereus
- Melaniparus griseiventris
- Melaniparus guineensis
- Melaniparus leucomelas
- Melaniparus leuconotus
- Melaniparus niger
- Melaniparus rufiventris
- Melaniparus thruppi
- Melanitta
- Melanitta americana
- Melanitta deglandi
- Melanitta deglandi stejnegeri
- Melanitta fusca
- Melanitta nigra
- Melanitta perspicillata
- Melanitta stejnegeri
- Melanocharis
- Melanocharis arfakiana
- Melanocharis crassirostris
- Melanocharis longicauda
- Melanocharis nigra
- Melanocharis striativentris
- Melanocharis versteri
- Melanocharitidae
- Melanochlora
- Melanochlora sultanea
- Melanocichla
- Melanocichla calva
- Melanocichla lugubris
- Melanocorypha
- Melanocorypha bimaculata
- Melanocorypha calandra
- Melanocorypha leucoptera
- Melanocorypha maxima
- Melanocorypha mongolica
- Melanocorypha yeltoniensis
- Melanodera
- Melanodera melanodera
- Melanodera melanodera melanodera
- Melanodera xanthogramma
- Melanodryas
- Melanodryas cucullata
- Melanodryas vittata
- Melanopareia
- Melanopareia bitorquata
- Melanopareia elegans
- Melanopareia maranonica
- Melanopareia maximiliani
- Melanopareia torquata
- Melanopareidae
- Melanopareiidae
- Melanoperdix
- Melanoperdix nigra
- Melanoptila
- Melanoptila glabrirostris
- Melanorectes
- Melanorectes nigrescens
- Melanospiza
- Melanospiza bicolor
- Melanospiza bicolor omissus
- Melanospiza richardsoni
- Melanotis caerulescens
- Melanotis hypoleucus
- Melanotrochilus fusca
- Melanotrochilus fuscus
- Meleagrididae
- Meleagris
- Meleagris gallopavo
- Meleagris ocellata
- Melghat
- Melghat Tiger Reserve
- Meliarchus sclateri
- Melichneutes
- Melichneutes robustus
- Melidectes
- Melidectes belfordi
- Melidectes foersteri
- Melidectes fuscus
- Melidectes leucostephes
- Melidectes nouhuysi
- Melidectes ochromelas
- Melidectes princeps
- Melidectes rufocrissalis
- Melidectes sclateri
- Melidectes torquatus
- Melidectes whitemanensis
- Melidora
- Melidora macrorrhina
- Melierax
- Melierax canorus
- Melierax gabar
- Melierax metabates
- Melierax poliopterus
- Melignomon
- Melignomon eisentrauti
- Melignomon zenkeri
- Melilestes
- Melilestes megarhynchus
- Meliphacator
- Meliphacator provocator
- Meliphaga
- Meliphaga albilineata
- Meliphaga albonotata
- Meliphaga analoga
- Meliphaga aruensis
- Meliphaga cinereifrons
- Meliphaga flavirictus
- Meliphaga fordiana
- Meliphaga gracilis
- Meliphaga lewinii
- Meliphaga mimikae
- Meliphaga montana
- Meliphaga notata
- Meliphaga orientalis
- Meliphaga reticulata
- Meliphaga vicina
- Meliphagidae
- Melipotes
- Melipotes ater
- Melipotes carolae
- Melipotes fumigatus
- Melipotes gymnops
- Melithreptus
- Melithreptus affinis
- Melithreptus albogularis
- Melithreptus brevirostris
- Melithreptus chloropsis
- Melithreptus gularis
- Melithreptus gularis laetior
- Melithreptus laetior
- Melithreptus lunatus
- Melithreptus validirostris
- Melitograis
- Melitograis gilolensis
- Mellby Orr (Oland)
- Mellby Orr (Öland)
- Mellby Örr (Öland)
- Meller's Duck
- Mellisuga
- Mellisuga helenae
- Mellisuga minima
- Melloria
- Melloria quoyi
- Melocichla
- Melocichla mentalis
- Melodious Babbler
- Melodious Blackbird
- Melodious Bushlark
- Melodious Lark
- Melodious Laughing-thrush
- Melodious Laughingthrush
- Melodious Warbler
- Melophus
- Melophus lathami
- Melopsittacus
- Melopsittacus undulatus
- Melopyrrha
- Melopyrrha nigra
- Melopyrrha nigra nigra
- Melospiza
- Melospiza georgiana
- Melospiza lincolnii
- Melospiza melodia
- Melospiza melodia gouldii
- Melozone
- Melozone aberti
- Melozone albicollis
- Melozone biarcuata
- Melozone biarcuatum
- Melozone cabanisi
- Melozone crissalis
- Melozone fusca
- Melozone fusca texanus
- Melozone kieneri
- Melozone leucotis
- Mendon Ponds Park
- Mendoza Monarch
- Menetries' Warbler
- Menetries's Warbler
- Mengkoka Honeyeater
- Menorca
- Mentawai Scops-Owl
- Mentawai Scops Owl
- Mentocrex beankaensis
- Mentocrex kioloides
- Mentrocrex kioloides
- Menura alberti
- Menura novaehollandiae
- Menuridae
- Mercantour National Park
- Mercantour National Park France
- Mere Sands Wood
- Merganetta
- Merganetta armata
- Merganetta armata armata
- Merganser
- Mergellus
- Mergellus albellus
- Mergus
- Mergus albellus
- Mergus australis
- Mergus cucullatus
- Mergus merganser
- Mergus merganser merganser
- Mergus merganser orientalis
- Mergus octosetaceus
- Mergus serrator
- Mergus squamatus
- Merida Brush Finch
- Merida Brushfinch
- Merida Flowerpecker
- Merida Flowerpiercer
- Merida Hemispingus
- Merida Speckled Teal
- Merida Sunangel
- Merida Tapaculo
- Merida Wren
- Merja Zerga National Park
- Merja Zerga National Park Morocco
- Merlin
- Meropidae
- Meropogon
- Meropogon forsteni
- Merops
- Merops Orientalis
- Merops albicollis
- Merops americanus
- Merops apiaster
- Merops boehmi
- Merops breweri


