- Macaroni Penguin
- Magellanic Oystercatcher
- Magellanic Penguin
- Magellanic Snipe
- Magnificent Frigatebird
- Magpie Shrike
- Malachite Kingfisher
- Mallard
- Maned Duck
- Mangrove Warbler
- Many-banded Aracari
- Marabou Stork
- Marico Sunbird
- Martial Eagle
- Masked Lapwing
- Meadow Pipit
- Mealy Amazon
- Medium Ground Finch
- Mexican Violetear
- Mocking Cliff Chat
- Montezuma Oropendola
- Mountain Thrush
- Mourning Collared Dove
- Mourning Sierra Finch
- Mute Swan