Study
Allometry of Alarm Calls: Black-Capped Chickadees Encode Information About Predator Size
Templeton, C. N.; Greene, E.; Davis, K.
Science, 2005
Live raptors of thirteen species, spanning a wide range of body sizes, were presented one at a time to captive chickadee flocks and the resulting mobbing calls recorded. The number of terminal "dee" notes was measured against predator size. Recorded calls were then played back to wild flocks with no predator present.
- Studied in
- Poecile atricapillus
- Sample size
- 13 live raptor species presented, with playback to wild flocks
Smaller, more manoeuvrable raptors — the ones that actually threaten a chickadee — produced calls with more "dee" notes. On playback, wild birds mobbed more intensely in response to calls with more notes, in the complete absence of any predator.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
The call encodes graded information about the degree of threat, and receivers extract and act on that information.
How NatureHQ reads it
The reason to carry this alongside the vervet work is that it closes the loop in a way headlines rarely report. The first half is analysis — more notes for smaller hawks — and on its own it is only a correlation in a spectrogram. The second half is the playback, where birds that could not see any hawk still adjusted their behaviour to the number of notes. Analysis found the pattern; the experiment showed it was a pattern the birds themselves use.
- Predator presentations were to captive flocks; the playbacks were to wild ones.
- How the note count is produced — whether it is under voluntary control — is not addressed.
- Graded information about threat is a much weaker claim than a name or a word, and the two are routinely conflated in coverage of this work.
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Animal communication
A call only counts as carrying information once another animal has been shown to act on it — not when a pattern is found in the recording.
Mobbing
Nuthatches listening to chickadee alarm calls do not just hear that something is wrong. They read how alarmed the chickadee is, and adjust their own response to match the threat encoded in the call.
Published by: American Association for the Advancement of SciencePublished in Science or Science Advances (AAAS).
doi.org/10.1126/science.1108841
Checked against Crossref 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 2026-08-31.