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 A male songbird's tune¹ advertises his status and availability to choosy female. But rock sparrows offer a notable exception. Their crooning can also reveal when the male has been jilted. Researchers studied the songs of male rock sparrows in the French Alps. These sparrows have a simple song. One element repeated several times as you can hear in this young male. When the researchers compared a male's song to his success in siring chicks, they found subtle surprises. Older sparrows who have slower-paced, higher pitched songs than younger birds sire the most chicks. This suggests females use other cues such as physical appearance in selecting the best mate. In an added twist, males whose mates have paired off with  another bird sing louder than males with faithful female. This is the first known case of an inverse² link between bird song volume and male's nesting success. The study is in the Journal PLoS ONE.  The male isn't just singing his sorrow, however. The researchers propose that the male raises his voice in a desperate attempt to call back his partner, the rock sparrow version of late-night drink-and-dial.