A study into the birdsong of the zebra finch has found male birds can deceive newly encountered females by exaggerating their physical condition using their song.
Males in good condition sang at a higher rate than those in poor condition in front of their partners but the study found no difference in the songs of single male birds when encountering unknown females.
Singing can be used as a test for the condition of birds due to the energy required to sustain a high song rate for longer.
Read more at University of Exeter