Aug. 12, 2013 — Older male nightingales perform faster and more demanding trills than their younger rivals. These findings were published by researchers at the University of Basel and the Netherlands Institute of Ecology in the online edition of Journal of Avian Biology. With up to 100 trill elements a second, nightingales belong to the fastest singers.
Nightingales are famous for their large song repertoire: Each male can perform around 200 different song types. Facing this great variety, how can a female listener assess correctly if the male counterpart is a suitable mating partner? It is unlikely that the size of the repertoire is used as a performance indicator, since it would take about one hour for a male nightingale to sing through its whole song list. Thus, it is more likely that the quality of certain elements or song types are attended to for quick assessment.
Around 20 percent of nightingale songs contain rapid broadband trills that are characterized by particularly large frequency bandwidths. Since the performance of these sounds is very demanding, the rate at which they can be repeated is limited: "Trying to sing rapidly increasing sounds in fast repetition is very hard for us humans as well," says PD Dr. Valentin Amrhein, Zoologist at the University of Basel and head of the research station Petite Camargue Alsacienne in which the data was collected. Singing rapid broadband trills comes at a certain price for the male nightingale. Thus, it is suggested that males in good physical condition trill better and that therefore, trilling is a good indicator for male "quality."