Species as the Organism Blueprint
Inbred canaries sang songs with less pure tones, and at slightly different pitches, than their outbred cousins—and female canaries seemed to be able to tell the difference.
Inbred Songbirds Croon out of Tune
Just like humans have to learn to talk, songbirds aren't just born singing—they have to learn to carry a tune. "So in the beginning they just babble." Raissa de Boer, a behavioral ecologist at the University of Antwerp in Belgium. "And they learn from a tutor, so they need an example song in order to learn it."