Domestication effects on behavioural traits and learning performance: comparing wild cavies to guinea pigs

Abstract

The domestication process leads to a change in behavioural traits, usually towards individuals that are less attentive to changes in their environment and less aggressive. Empirical evidence for a difference in cognitive performance, however, is scarce. Recently, a functional linkage between an individual's behaviour and cognitive performance has been proposed in the framework of animal personalities via a shared risk-reward trade-off. Following this assumption, bolder and more aggressive animals (usually the wild form) should learn faster. Differences in behaviour may arise during ontogeny due to individual experiences or represent adaptations that occurred over the course of evolution. Both might singly or taken together account for differences in cognitive performance between wild and domestic lineages. To test for such possible linkages, we compared wild cavies and domestic guinea pigs, both kept in a university stock for more than 30 years under highly comparable conditions. Animals were tested in three behavioural tests as well as for initial and reversal learning performance. Guinea pigs were less bold and aggressive than their wild congeners, but learnt an association faster. Additionally, the personality structure was altered during the domestication process. The most likely explanation for these findings is that a shift in behavioural traits and their connectivity led to an altered cognitive performance. A functional linkage between behavioural and cognitive traits seems to exist in the proposed way only under natural selection, but not in animals that have been selected artificially over centuries.

Stereotypic behaviours in Melopsittacus undulatus: Behavioural consequences of social and spatial limitations

“…Similar phenomena have been noted for a wide range of animal taxa (Wurbel et al, 2006), including Passeriformes and humans . In support of this hypothesis, two recent studies on the American mink and the Guinea pig, species intensively bred for commercial and pet purposes, have demonstrated that individuals can be selected to minimize their stereotypic and aggressive behaviours, resulting in improved health and wellbeing (Hansen et al, 2010;Brust and Guenther, 2014).…”

Stability of the guinea pigs personality – cognition – linkage over time

“…If performance across tasks is repeatable, we would expect positive relations between sociopositive behaviour and learning as well as between boldness and aggressiveness, as detected in our earlier paper (Brust & Guenther 2015), to be also stable over time. However, if we find performance to be instable over time, we would not expect a consistent linkage between the classical personality traits and cognition.…”

“…This procedure has proved to work well for single testing these highly social mammals in a number of previous studies (e.g. Brust & Guenther 2015;Guenther et al 2013). Stimuli were presented on a brick that was integrated into the bedding of the home cage and provided a flat surface.…”

“…A recent study has shown that aggressiveness and sociopositive behavior is rank-order stable and can be interpreted as personality traits in guinea pigs (Zipser et al 2013). In an earlier study, we already showed that sociopositive behavior was correlated with learning in guinea pigs (Brust & Guenther 2015). Guinea pigs that learned to associate a reward with a visual cue faster did show more sociopositive behaviour towards an unfamiliar conspecific than slower learners.…”

“…The inter test interval was 30-33 days. In the test sociopositive (nudging, naso-nasal and naso-anal sniffing) and aggressive contacts (fixation of the conspecific with the eyes, demonstrating a curved body posture, chasing, teeth chattering, attacking and snapping) with an unknown same sex conspecific were counted by a direct observer who was not involved in the learning tests (see also Brust & Guenther 2015). For testing, individuals were separated from their group mates in the dividable section of their home cage.…”