Eye-ringed Flatbill

The eye-ringed flatbill is 15 to 17 cm (5.9 to 6.7 in) long and weighs 21 to 23 g (0.74 to 0.81 oz). The sexes have almost the same plumage. Adults have a bold white eye-ring, a faint dark smudge below the eye, grayish lores and cheeks, and a dusky patch behind grayish ear coverts. The rest of their head and their entire upperparts are olive-green. Their wings and tail are dusky with paler yellow-olive edges on the feathers. Males have stiff comb-like barbs on the outer primaries; females lack them. Voice: The eye-ringed flatbill is "secretive and hard to locate" except by voice. Its vocalizations include "a thin, buzzy, insect-like zweeeeeeee-zweeeee (each part slightly rising) or zeeeee-zeeeee-zeeeee-zweeeeee!, just a single zeeeeee a high-pitched whistle, sweeeeet!".