- Magnificent Frigatebird
- Malagasy Turtle Dove
- Mallard
- Mandarin Duck
- Mangrove Warbler
- Many-colored Rush Tyrant
- Many-spotted Hummingbird
- Marbled Godwit
- Marsh Tit
- Mascarene Martin
- Meadow Pipit
- Mediterranean Gull
- Meller's Duck
- Melodious Warbler
- Middle Spotted Woodpecker
- Military Macaw
- Mistle Thrush
- Mitred Parakeet
- Monk Parakeet
- Mountain Bluebird
- Mountain Caracara
- Mountain Chickadee
- Mourning Dove
- Mourning Sierra Finch
- Moussier's Redstart
- Muscovy Duck
- Mute Swan