Slender, long-tailed bird that is more often heard than seen. Brown above and white below, with a yellow bill. Look for the large white spots on underside of tail. Wings flash rufous, especially obvious in flight. Stealthy and shy in dense forests and riparian areas, often sitting motionless for long periods of time. Feeds mainly on caterpillars and other insects. Uncommon but widespread breeder across much of North America; more southerly distribution than Black-billed Cuckoo. Winters in South America, where care should be taken to separate from very similar Pearly-breasted Cuckoo, which lacks rufous tones in wing. Separated from Black-billed Cuckoo by bill color, wing color, and tail pattern. Listen for its hoarse cooing song and knocking calls.