Updates are available Correction dated 2025-07-26

Article History

Received: 17 September 2024

Revised: 16 December 2024

Accepted: 19 December 2024

First Online: 2 January 2025

Change Date: 31 July 2025

Change Type: Update

Change Details: The original online version of this article was revised to update Conflict of Interest statement.

Change Date: 26 July 2025

Change Type: Correction

Change Details: A Correction to this paper has been published:

Change Details: https://doi.org/10.1007/s10071-025-01996-5

Declarations

:

: This research was approved by ethical review boards at the University of St Andrews, Twycross Zoo, and the Budongo Research Unit at Edinburgh Zoo. All great-ape research at these institutions is non-invasive and strictly adheres to the ethical standards of the institutions, the University of St Andrews, the legal requirements of the United Kingdom and to the World Association of Zoos and Aquariums Ethical Guidelines for the Conduct of Research on Animals by Zoos and Aquariums. The apes live in species-typical social groups with access to both indoor and outdoor spaces with vegetation. They receive regular produce feedings throughout the day alongside additional enrichment and are familiar in non-invasive cognitive testing. Participation in experiments is entirely voluntary and at no point are subjects separated from the group for research purposes, nor are they deprived of either food or water. Testing takes place in a communal area accessible to all group members and subjects are never separated from their group for research purposes.

: Josep Call is an editor for the journal and has not taken part in the manuscript’s peer review process.