![Greenfinch Greenfinch](http://www.planetofbirds.com/wp-content/uploads/2012/02/Greenfinch.jpg)
Greenfinch
The song of passerine birds is a conspicuous and exaggerated display shaped by sexual selection in the context of male-male competition or mate attraction. At the level of the individual, song is considered an indicator of male ‘quality’.
Greenfinch