A giant, round-headed, ginger-rufous owl covered by dusky bars, spots, and chevrons. Quite shy; day-roosts are well-hidden in huge trees along permanent rivers and forested swamps with sluggish backwaters. The call is a deep, low, horn-like “Ooom”; also produces a series of grunts. Young birds sometimes emit an eerie screeching: “wheeeuuu”. Similar Rufous Fishing-Owl is smaller and brighter; it lacks bars and chevrons on the underparts. Vermiculated Fishing-Owl has a heavily-streaked upper breast and a pale-yellow (not black) beak.