The flammulated owl (Otus flammeolus) is a tiny, common predator on invertebrates that nests in cavities in western North American coniferous forests. It was thought by early workers to be rare (Bendire 1892, Bent 1938), but more recent opinion is that it is common but secretive (Marshall 1967, Winter 1971, 1974, Richmond et al. 1980). The combination of its very small size (Earhart and Johnson 1970), ventriloquial but low-pitched voice (Miller 1947), strictly invertebrate diet (Ross 1969, but see below), and probable migratory behavior (Winter 1974, Balda et al. 1975, but see Johnson 1963) suggests an unusual adaptive strategy. Understanding all aspects of this strategy will lead to wise management decisions.