Study
The function(s) of bird song
Kroodsma, Donald E.; Byers, Bruce E.
American Zoologist, 1991
A synthesis of the experimental literature on why birds sing, covering territory defence, mate attraction, mate stimulation and within-pair communication, and examining how well the evidence for each is supported by manipulation rather than correlation.
- Studied in
- Passeriformes
- Sample size
- synthesis of experimental and comparative work on song function
Territory defence and mate attraction are both supported by direct experiment in multiple species. Many other proposed functions — and most claims about what repertoire size specifically achieves — rest on correlational evidence that admits several readings.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Song has multiple functions that vary by species and context, and the field has been quicker to propose functions than to test them.
How NatureHQ reads it
Useful mainly as a corrective. "Birds sing to attract mates and defend territory" is the standard summary and it is broadly right, but the confidence attached to the more specific versions — that a larger repertoire wins more mates, that song complexity signals quality — is not always earned by the evidence behind them. This review is the place where the difference between the demonstrated core and the plausible surround is set out most plainly.
- A review; it inherits the taxonomic and geographic biases of the work it covers, which is heavily temperate and northern.
- Predates most of the work on female song and duetting, and on urban acoustic adaptation.
- Function in this literature usually means current utility rather than evolutionary origin, and the two are routinely conflated in secondary coverage.
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Birdsong
Song holds a territory by itself. Remove the bird, leave a loudspeaker playing its song, and rivals stay away for longer.
The dawn chorus
Birds sing at dawn for several reasons at once — poor light for feeding, still air that carries sound further, and a moment when signalling is worth most — and no single explanation accounts for it.
Published by: University press journalsPublished in a university press journal.
Checked against Crossref and OpenAlex on 2026-09-28, and they agree on the title, the authors and the year.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-09-02.