The Grey-cheeked Nunlet, a member of the Bucconidae family, is a small bird with a length of 14 to 15 cm and a weight ranging from 14.5 to 19.5 grams. It is characterized by its very dark chestnut crown, plain brown upperparts that are lighter on the rump, and a face mostly cloaked in grey, accentuated by a ring of bare red skin encircling the dark brown eye. The tail is a dark brown, verging on black at the tip, while the underparts display a rufous hue on the chin, throat, breast, and flanks, transitioning to a buffy belly. Its bill is predominantly blue-gray, and the feet are a subdued brown or greenish gray.
To identify the Grey-cheeked Nunlet, look for the distinctive dark chestnut crown and the grey face with a red ring around the eye. The rufous underparts and buffy belly, along with the blue-gray bill, are also key features to distinguish this species from others.
This species thrives in a variety of forested environments, from moist to humid primary and secondary forests to gallery forests and dense thickets. It shows a particular preference for woodlands along rivers and is typically found at lower forest levels, though it may venture up to the subcanopy.
The Grey-cheeked Nunlet's range is somewhat limited, stretching from central Panama to north-central Colombia. It is found at elevations from sea level to 1,000 meters.
While the feeding behavior of the Grey-cheeked Nunlet is not well-documented, it has been observed preying on various arthropods and occasionally joins mixed-species foraging flocks.
The song of the Grey-cheeked Nunlet is a plaintive and measured series of up to 20 notes, reminiscent of a 'weeip weeip, weeip…'.
Breeding season for the Grey-cheeked Nunlet occurs from February to June in Colombia. However, details on its breeding phenology are scarce. The nesting behavior of its genus is generally not well understood, but related species are known to nest in shallow scrapes covered with twigs and leaves, with clutch sizes typically around four eggs.
The IUCN has classified the Grey-cheeked Nunlet as Least Concern. Despite this, the population is estimated to be under 50,000 mature individuals and is on a declining trend. The species is considered uncommon to rare in Panama but is generally fairly common in Colombia.