27 de julho de 2016

Inbred Songbirds Cannot Carry A Tune


Female songbirds choose mates based on their songs, and this study provides some insights into what aspects of song they use to identify a “quality” male
Resultado de imagem para timbrado espanhol
A domestic canary (Serinus canaria forma domestica). (Credit: Youtube.)
When a female chooses a mate, she is looking for a male who possesses a set of characters that makes him attractive. In songbirds, one of the primary characters that females use to choose a mate is the quality of his song. But many songbirds learn their songs from older males, which points to the familiar and longstanding “nature versus nurture” debate: does quality result from growing up in a good environment or it is based solely upon having good genes? And hand-in-hand with that argument comes another question: what aspect of a male’s song is important to a female songbird?
Just what do females want?
Like a male peacock’s huge, colorful tail (or like an expensive red sportscar), ornaments that reflect a male’s quality are necessarily costly to the male in ways that test his survival (or credit rating), thereby creating an honest signal that reflects his overall quality as a mate (ref). Males who overcome this “handicap” long enough to breed are reliably of higher quality than are males who lack these expensive ornaments — or who do not survive long enough to breed.
But when it comes to mate choice, what, exactly, is “quality”?
“‘Quality’ is determined by genetic and environmental factors”, write the authors in their paper, which was published today in theProceedings of the Royal Society B.
But how genetics and environment influence each other are poorly known.
“[S]urprisingly there is very limited evidence if, and how, genetic aspects of male quality are reflected in song”, write the authors.