Australian Breeders MarketStress factors effect bird song repertoires
The New Scientist (UK) has reported on studies that state food depravation in early stages of growth prevent the areas of the brain that control bird songs from developing properly.
Studying sparrows, starlings and zebra finches, birds suffering from food depravation and other stress factors could not learn and reproduce songs required to attract mates.
They theorise that this may be a natural response, as females will be less likely to be attracted to males that are less healthy than there full throated songbird rivals.
So breeders, fatten those babies up early.