“These findings are in line with recent scientific literature about wild and captive primates, and they show that less socially integrated individuals are less likely to obtain resources such as food, but they are more likely to overcome neophobia —aversion to new things—, to improve their situation. Also, this confirms that ungulates are a promising taxon to test evolutionary theories with a comparative approach”, says Álvaro López Caicoya, predoctoral researcher at the Faculty of Psychology and the Institute of Neurosciences (UBneuro) of the UB and first author of the article.
Regarding this issue, the researcher states that most comparative studies on the evolution of cognitive abilities have been conducted on birds and primates, but that evolutionary pressures to which these are subjected may be different from those of other species. Therefore, including other taxa —such as ungulates— in future studies is “essential for understanding the limits and the generalization of specific evolutionary hypotheses”.
The study, published in the journal Proceedings of the Royal Society B, includes the participation of Montserrat Colell, lecturer at the Faculty of Psychology and researcher at UBneuro, together with other experts from the Max Planck Institute for Evolutionary Anthropology and the University of Leipzig (Germany).
An experiment with a hundred animals in captivity
The experiment was carried out on 111 animals from 13 different species, among which there were goats, dromedaries, Przewalki horses, giraffes, llamas, sheep and deer, among other ungulates, which lived in captivity in the zoos of Barcelona, Barbent (France), Nuremberg and Leipzig (Germany). Each of these groups of animals had to deal with a test, consisting opening a type of container they did not know and which contained their favourite food.
All the animals had previously been classified according to several aspects that could have an impact on their ability to solve problems, such as the fear of new objects, the diet and the social integration in the group. The aim was to identify the individual and socio-ecological characteristics of the animals that were most successful when working on the challenge the researchers had prepared.
Dromedaries and goats, the most skilled
The participation in the experiment varied between species: while 100% of the dromedaries approached the container, only 33% of the sheep did. But the species that showed the most interaction were the domesticated ones and those with a greater fission-fusion dynamic (those belonging to complex groups that go together or separate depending on the environment and the time). However, these characteristics were not indicators of a higher ability to solve the challenge they encountered. “The domestication process could have specifically selected specifically the traits and features that facilitate interactions with humans (and human artefacts), but not the cognitive skills that allow for a more efficient problem solving”, note the researchers.
Finally, out of the hundred animals that participated in the experiment, only 36% could open the container and access the food at least once. “Species with a higher percentage of individuals that escaped were dromedaries and goats, with 86% and 69%, respectively”, highlights Álvaro López Caicoya.
In successful cases, the researchers assessed the diversity of resources used to solve the challenge. “Most of them opened the containers using their nose, muzzle or lips; only nine out of these forty animals used more than one strategy to solve the challenge, such as lifting the cover gently with their lips or throwing the cup to the floor”.
A pioneering study
This paper is a pioneering study in the research on the ungulates’ cognition, since “there are barely a handful of similar studies” with these species. “Traditionally, they have been considered cattle and their behaviour or their understating have not been of interest. Thanks to this and other studies, we are starting to see these are animals with complex behaviours which that are worth studying”, stresses Álvaro López Caicoya.
In this sense, the UB researcher highlights the need for more studies that include more species and individuals, both in captivity and wild ones, and more complex challenges, to generalize the findings. “The ungulates are an exceptional model for the comparative research and this study is only a first approach to the cognition of these species”, he concludes.
Caicoya, A. L.; Schaffer, A.; Holland, R.; von Fersen, L.; Colell, M.; Amici, F. “Innovation across 13 ungulate species: problem solvers are less integrated in the social group and less neophobic”, Proceedings of the Royal Society B, April 2023. Doi: 10.1098/rspb.2022.2384