The Vermiculated Screech-Owl is a small, finely-marked owl of lowland and lower montane forest. It occurs in several disjunct populations, which are often divided into separate species. The M. g. "guatemalae" group occurs from Mexico south to Nicaragua, M. g. vermiculatus is found from Costa Rica to northern Colombia and northern Venezuela, M. g. roraimae occurs in the tepuis of southern Venezuela and northern Brazil, and M. g. napensis is found along eastern Andean slopes from Ecuador to Bolivia. Populations differ largely in vocal characters. All populations are often heard calling shortly after dusk, and can sometimes be spotlighted on perches at relatively low levels and in dense vegetation.