A tiny bird, probably the smallest in Extremadura, it has mossy green upperparts, whitish underparts, with a pale buff diffusion, and a bold white supercilium, bordered by black. The centre of the crown has an orange-yellow patch. It has a short, fine bill adapted to find insect larvae in the cracks of bark. It breeds in pinewoods and oak woods in the north of Extremadura, whereas in the winter they can also be seen at lower altitudes throughout the region.