Data from: Communication value of mistakes in dark-eyed junco song

Sexual signals contain information on individual quality or motivation,
and most explanations for their reliability are based on signal costs. A
recent suggestion is that signaling mistakes, defined as deviations from
typical signal design, provide cues on individual quality, contributing to
reliable communication even when signal design is not costly. We describe
several atypical song traits in dark-eyed juncos (Junco hyemalis) that may
be mistakes during song production or development and occur in up to 6% of
songs. These putative mistakes were more frequent in an urban versus a
wildland population, and individuals differed in their frequency of
mistakes. Some atypical signals were more frequent in younger males or
were negatively related to paternity success, supporting the hypothesis
that fewer mistakes indicate individual quality. We also discuss
unexpected results, such as some atypical signals being more frequent in
more ornamented males and in songs with lower performance demands. Song
consistency (similarity across syllable renditions) was positively related
to male age and paternity success; nonetheless, relations with paternity
were stronger when looking at the most deviant syllable renditions,
suggesting that the perceptual salience of large mistakes may mediate
receiver responses to song consistency. Results indicate that signaling
mistakes reveal relevant information to play a role in communication.