Study
Song repertoires and territory defence in the great tit
Krebs, John R.; Ashcroft, Richard; Webber, Michael
Nature, 1978
Great tit territories in a woodland were experimentally vacated by removing the resident males. Some were then broadcast with recorded great tit song from loudspeakers, some with a control sound, and some left silent. The rate at which new birds moved in was measured.
- Studied in
- Parus major
- Sample size
- vacated woodland territories assigned to playback and control treatments
Territories broadcasting song were re-occupied substantially more slowly than silent or control-sound territories.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Song functions in territory defence: it keeps rivals out in the absence of the singer himself.
How NatureHQ reads it
The experiment that converts a plausible story into a demonstration. Everyone assumed birds sing to hold territory, and correlational evidence cannot separate that from song simply being what a bird with a territory happens to do. Removing the bird and leaving the sound is the manipulation that isolates the signal — the intruders are responding to the song and nothing else, because there is nothing else. It is the same logic as the playback designs used throughout animal communication, run at the scale of a wood.
- One species in one habitat, and a temperate species with a small repertoire.
- Loudspeaker song is stationary and unresponsive; a real resident replies, moves and escalates.
- The design tests the deterrent function and says nothing about the mate-attraction function, which is the other half of what song is usually for.
Removing the bird and leaving the song behind
Does song actually keep rivals out of a territory, or is singing just what a bird holding a territory happens to do?
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Published by: Nature PortfolioPublished in a Nature Portfolio 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.