Cuckoo in Fausset's Bible Dictionary

shachaph; Leviticus 11:16; Deuteronomy 14:15; unclean. Rather the Greek cepphus of Aristotle, a large petrel, as the Puffinus cinereus. From a root "to be slender", "light of body" like a gull, whose body is small compared with its apparent size and outspread wings; it skims the waves, seeking its food in the agitated water. Andouini's gull, abounding on the shores of Syria (Tristram), a more likely bird than the storm petrel, which is seldom seen on land.