Schaffer, Alina
Caicoya, Alvaro L.
Colell, Montserrat
Holland, Ruben
von Fersen, Lorenzo
Widdig, Anja
Amici, Federica http://orcid.org/0000-0003-3539-1067
Funding for this research was provided by:
Max Planck Institute for Evolutionary Anthropology
Article History
Received: 29 January 2021
Revised: 25 May 2021
Accepted: 27 May 2021
First Online: 23 June 2021
Declarations
:
: The study was approved by the welfare managers at the zoos of Barcelona, Barben, Nuremberg, and Leipzig, who controlled and approved all the procedures. The study was mainly observational, all the animals participated on a completely voluntary basis, individuals were not separated from their social group,s and no invasive procedures were used. Therefore, no formal approval was required. During the task, individuals were never water or food deprived, and motivation to participate was ensured exclusively by the use of highly preferred food belonging to their natural diets. The experiments thus provided a form of enrichment for the subjects and did not present any risks or adverse effect. The study was carried out in accordance with the national regulations of all the countries in which the study took place.
: Not applicable.
: Not applicable.
: Not applicable.