Mouse-colored Tyrannulet

The mouse-colored tyrannulet is 10.5 to 12.5 cm (4.1 to 4.9 in) long and weighs about 7 to 12 g (0.25 to 0.42 oz). The sexes have the same plumage. Adults of the nominate subspecies have an olive-brown to gray-brown crown, a wide but ill-defined whitish to creamy supercilium, and a thin whitish eye ring on a face that is otherwise pale grayish white to white. Their upperparts are olive-brown to gray-brown. Their wings are dusky with wide whitish to dull cinnamon edges on the innermost flight feathers and tips on the coverts. Their tail is dusky. Their throat is pale grayish white to white. Voice: The mouse-colored tyrannulet's dawn song is a "short husky phrase of some 3‒5 notes which is repeated for a long period rwee-chee-chew....tsee-rwee-chee-chew.....rwee-chee-chew...". Its day song is a "rising series of buzzy notes that increase in amplitude till the last few notes, which are variable in pitch and amplitude chu-chu-chu-chu-chu-chee!-chu-chew". It also makes a nasal "tjew-tjew-tju...