To our ear, the haunting song of this Hermit Thrush is musical, even ethereal. To another Hermit Thrush, the song signals that a male is laying claim to a territory and seeking a mate. These thrushes, like other songbirds, broadcast a variety of calls. Call notes can signal many things – alarm at a predator or aggression toward a rival. Or they may simply maintain contact between members of a pair or flock. So the next time you hear a bird sing or call, listen carefully. You may be introduced to a whole new vocabulary.What birds are singing and calling around your home? Let us know on Facebook.More info and transcript at BirdNote.org. Want more BirdNote? Subscribe to our weekly newsletter. Sign up for BirdNote+ to get ad-free listening and other perks. BirdNote is a nonprofit. Your tax-deductible gift makes these shows possible.