A first exploratory comparison of the behaviour of wolves (Canis lupus) and wolf-dog hybrids in captivity.

"Declarations Conflict of interestThe authors have no competing interests or other interests that might be perceived to influence the results and/or discussion reported in this paper. Ethical approvalThe study was carried out in accordance with the national regulations of all the countries in which the study took place. The experimental procedures were approved by the research coordinators (at the Osnabrück Zoo, in Germany) and the directors of the facilities (at the Riserva Naturale Regionale Lago di Penne and at the Parco Faunistico del Monte Amiata, in Italy). The risk assessment was conducted together by the research coordinators and the keepers working with each study group, and permission was only granted if they considered that the experimental procedures posed no risks to the animals and instead provided them with clear benefits in terms of enrichment. Individuals participated on a completely voluntary basis, they were never separated from the other group members, and they were never water or food deprived to facilitate participation. The experiments were thus considered to provide no risks or adverse effects to the subjects, and were regarded as a form of enrichment. Conflict of interest The authors have no competing interests or other interests that might be perceived to influence the results and/or discussion reported in this paper."

"Funding Open Access funding enabled and organized by Projekt DEAL."