Mouse-colored Antshrike
Thamnophilus murinus
The mouse-colored antshrike is 13 to 14 cm (5.1 to 5.5 in) long and weighs 17 to 20 g (0.60 to 0.71 oz). Members of genus Thamnophilus are largish members of the antbird family; all have stout bills with a hook like those of true shrikes. This species exhibits significant sexual dimorphism. Adult males of the nominate subspecies have gray upperparts with a hidden white patch between their scapulars. Their wings are dark yellowish brown that is somewhat rufous in the eastern part of its range; their wing coverts are grayer with buffy white tips. Voice: The mouse-colored antshrike's song is "slightly accelerating series of up to c. 15 similar notes". It has been written as "arr arr arr-arr wee'AWR". Its main call is "nasal and abrupt"; others are "a flat, raspy whine", "a clear note that becomes a raspy growl", "variable whines", and "abrupt notes".
ID text from Wikipedia, CC BY-SA 4.0

Rufous-capped Antshrike
Thamnophilus ruficapillus
The rufous-capped antshrike is 15 to 17 cm (5.9 to 6.7 in) long and weighs 16.3 to 25 g (0.57 to 0.88 oz). Members of genus Thamnophilus are largish members of the antbird family; all have stout bills with a hook like those of true shrikes. This species exhibits significant sexual dimorphism. Adult males of the nominate subspecies T. r. ruficapillus have a chestnut crown and a buffy gray face and throat with faint dusky mottling and bars. Their upperparts are dark brown. Their wings are rufous-brown. Their tail is brownish black with white tips and bars on the inner webs of the outer feathers. Voice: The rufous-capped antshrike's song apparently has some regional variations that have not been studied. It has been described as a "slightly accelerating series of 12-15 'tjew' notes". It has been written as "wah, nyah, nyah-nyah-nya-nya-nya'nya-arr" and as "weepweepweepweepweepweepeepeepeep".
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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Play today's Daily BirdPhotos and recordings are credited to their authors under the licence shown. Full profiles: Mouse-colored Antshrike and Rufous-capped Antshrike.