“Communication value of mistakes in dark-eyed junco song”

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André C. Ferreira, Jonathan W. Atwell, Danielle J. Whittaker, Ellen D. Ketterson, and Gonçalo C. Cardoso

Atypical birdsongs and singing mistakes give away valuable information for mates and competitors

Animal comunicaton! (oops) communication!

A male dark-eyed junco (Junco hyemalis) singing.
(Credit: David Levinson)

As in this title, animals sometimes make mistakes communicating. Recent research shows that those “mistakes” are informative, and might be used by other animals to decide, for example, with whom to mate.

While the ubiquity of birdsong in Spring makes for a bucolic pleasure, its actual purpose is for the singing birds (generally males) to persuade other birds to mate with them. Accordingly, songs of many species are long and elaborate to show off skill and good physical condition. Many bird species, however, have simple songs that are difficult to explain in the context of showing off skill and impressing listeners.

For example, the dark-eyed junco (Junco hyemalis), a common North American sparrow studied by researchers at CIBIO/University of Porto and Indiana University, has very simple songs: a single syllable repeated for about one and a half seconds. Attempts to relate acoustic properties of these songs with the quality, experience, or reproductive success of juncos have so far failed.

A recent study shows that, perhaps inadvertently, juncos sometimes leave a syllable incomplete, start alternating rather than repeating syllables, etc. These “mistakes” are rare, but should stand out to bird listeners that interact all day long. The researchers find that singing with fewer “mistakes” is related to aspects of male quality, such as age and experience. And males singing with fewer “mistakes” fertilize more eggs (both in their nests and in their neighbors’!), suggesting that females pay attention to these songs when making mating decisions.

The finding that communication “mistakes” indicate the quality of individuals may help to explain why some species have simple sexual signals. Since mistakes are easier to identify in simple, repetitive signals, you may benefit from using such simple signals to show off your absence of mistakes. Therein lies the indication of skill. Read the Article