Mountain leaf warbler 
Mountain tailorbird 
Mountain wagtail 
Mountain wheatear 
Mountain wren 
Mourning sierra finch 
Mourning warbler 
Mourning wheatear 
Mouse-colored antshrike 
Mouse-coloured penduline tit 
Moussiers Redstart 
Moustached antpitta 
Moustached Antwren 
Moustached brush finch 
Moustached flowerpiercer 
Moustached turca 
Moustached warbler 
Mrs. Gould's sunbird 
Mugimaki flycatcher 
Multicoloured tanager 
Munchique wood wren 
Musician wren 
Myrtle warbler 
Myzomela erythrocephala