Wiley, R. H., and R. Godard.   1995.   Ranging of conspecific songs by Kentucky warblers and its implications for interactions of territorial males.   Behaviour 133:   81-102.


Kentucky warblers (Oporornis formosus) each sing a single song pattern. To determine whether males could range (estimate the distance to) conspecific songs, we presented clean and reverberated versions of strangers' songs to 12 males in a factorial design.

To assess differences between the playbacks and the subjects' own songs or neighbors' songs, we measured differences in minimal repetition periods between repeated acoustic elements in songs, features that could contribute to assessment of reverberation.

Results indicated that Kentucky warblers can range conspecific songs and that similarity between playback songs and established neighbors' songs or a subject's own songs did not enhance this ability.

Direct evidence that males misjudged the distance to reverberated playbacks excluded other interpretations of the results based on differences in the detectability or habituation of clean and reverberated songs.

These results suggest further that assessment of reverberation is sufficient for ranging and that perceptual analysis of song is not necessarily linked to overt production. As a consequence, repertoires of songs do not necessarily promote interference between territorial neighbors.


Direct indications that subjects misjudged the locations of playbacks provide the strongest evidence for ranging. Interpretation of different intensities of response to clean and degraded playbacks must consider the consequences of degradation for habituation, detection, and recognition of signals as well as ranging.

These confounding alternatives also arise in interpreting the influence of familiarity with particular songs on responses to clean and degraded playbacks. Our results show that territorial Kentucky warblers can range conspecifics' songs, at least approximately, regardless of familiarity with the song pattern.

Kentucky warblers differ from species in previous studies of ranging in having a single song pattern each and from most other birds inhabiting forests in incorporating rapidly repeated elements in their songs. The latter attribute might be an evolutionary adaptation to facilitate ranging.

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