Study
Ravens attribute visual access to unseen competitors
Bugnyar, Thomas; Reber, Stephan A.; Buckner, Cameron
Nature Communications, 2016
Ravens cached food in a room with a peephole into an adjoining room. In the key condition the peephole was open and a competitor could be heard but not seen, so the bird had to work out that it might be watched without seeing anyone watching.
- Studied in
- Corvus corax
- Sample size
- 10 captive common ravens
Ravens hid food more quickly and guarded caches more when the peephole was open and sounds suggested a competitor, and not when the peephole was closed.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Ravens can attribute visual access to a competitor they cannot see, which is difficult to explain by reading the competitor's gaze or body language.
How NatureHQ reads it
The peephole is the whole design: it removes the usual objection that the bird is simply reacting to another animal's stare. That makes it one of the better pieces of evidence that a bird represents something about what another individual can perceive. It is still short of showing that ravens hold beliefs about beliefs, and this is about ravens — not crows.
- Captive birds with extensive experience of caching experiments.
- Whether the birds represented "he can see me" or a learned association with open peepholes remains debatable.
- Ten individuals.
The peephole test
Does a raven hiding food understand that another bird might be able to see it — even when it cannot see that bird?
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.
This reference was resolved automatically against Crossref and OpenAlex on 2026-08-11.
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