- Magnolia Warbler
- Mallard
- Manx Shearwater
- Marbled Godwit
- Marbled Murrelet
- Marsh Wren
- Martinique Thrasher
- Mealy Amazon
- Medium Ground Finch
- Medium Tree Finch
- Mekong Wagtail
- Merida Wren
- Merlin
- Mississippi Kite
- Montane Nightjar
- Mountain Bluebird
- Mountain Quail
- Mountain Wren
- Mourning Warbler
- Moustached Wren
- Musician Wren
- Myrtle Warbler