Study
Keeping track of time: evidence for episodic-like memory in great apes
Martin-Ordas, Gema; Haun, Daniel; Colmenares, Fernando; Call, Josep
Animal Cognition, 2010
Apes watched food being hidden in two locations — one a preferred but perishable item, the other a durable one — and were allowed to retrieve after short or long delays, testing whether they tracked what was hidden where and how long ago.
- Studied in
- Pan troglodytes, Pongo pygmaeus, Gorilla gorilla
- Sample size
- great apes tested on what-where-when retrieval after delays
Apes chose the preferred perishable food after short delays and switched to the durable option after long ones, integrating content, place and elapsed time in a single retrieval.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Great apes have episodic-like memory meeting the what-where-when criterion previously demonstrated in scrub jays.
How NatureHQ reads it
The what-where-when criterion is a behavioural test, and the "-like" in "episodic-like" is doing real work: it marks that the test cannot distinguish remembering an event from holding a structured record of it. NatureHQ keeps the hedge because the alternative — asserting that an ape re-experiences its past — is not something any behavioural experiment can establish, in an ape or in a jay.
- Small numbers of captive, heavily tested individuals.
- What-where-when performance does not establish subjective recollection.
- Elapsed-time tracking may use an interval timer rather than a memory of when.
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Published by: Springer journalsPublished in a Springer journal.
doi.org/10.1007/s10071-009-0282-4
This reference was resolved automatically against Crossref on 2026-08-11.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-09.