The aptly named Yellow-thighed Finch is a common understory bird of montane tropical wet forests above 1200 m. It is a true Central American endemic, found only in Costa Rica and western Panamá. Traveling in social groups and multi-species flocks, it feeds on nectar, insects, spiders, berries and proteinaceous Müllerian bodies. This finch readily pursues its diverse prey items out of the forest understory, into pastures, gardens and along forest edges, flicking its tail often. It wears a sooty, slaty gray on its back and underparts, and a deep black on its wings, long tail, head and throat. Its notable bright yellow thighs almost glow, contrasting sharply with the bird's dark remainder. Its songs are a jumbled mix of bubbly whistles and buzzes, repeated rapidly at length. In Spanish, it is called cerquero musliamarillo, sabanero de piernas amarillas, or saltón de muslos amarillos. Yellow-thighed Finch, and likely the congeneric Yellow-green Finch (P. luteoviridis), are closely related to the Atlapetes brush-finches and to Large-footed Finch (Pezopetes capitalis).