Although the Flammulated Owl (Otus flammeolus) is a wide-spread temperate and neo-tropical species, its basic biology is obscurely known. The literature on this species is scattered and somewhat fragmented. Little is available on the distribution and relative abundance of this owl throughout most of its range. Current knowledge of this owl is largely due to the work reported by Jacot (1931), Johnson (1962), Marshall (1939, 1957, 1967), A. Miller (1947), L. Miller (1936), Phillips (1942), Phillips, Marshall and Monson (1964) and Ross (1969).