Cognitive Research in Zoo‐Housed Chimpanzees: Influence of Personality and Impact on Welfare

Abstract

We monitored chimpanzee welfare during the introduction of on-exhibit cognitive research training and testing, as measured by behavior and interest in such training, and related individual variation to personality assessments. We observed 11 chimpanzees (six males; five females) over a 16-month period and compared their behavior across three conditions: (1) Baseline (nontraining/research situations) and (2) an on-going, off-exhibit program of Husbandry Training and (3) Research Pod Activities, on-exhibit, group training for cognitive testing. There was considerable individual variation in their interest levels during research sessions; females and those scoring higher for Openness were present more frequently (including those who actively participated and those who observed others participating), but interest did not vary in relation to rates of self-directed behaviors (SDBs), rank, or the level of social disruptions within the group (i.e. large-scale displays or fights). The frequency of SDBs was predicted by the Neuroticism personality factor, but did not differ across baseline and training contexts, indicating that these activities do not negatively impact welfare. We also explored vigilance as an indicator of social uncertainty, but social monitoring did not differ in relation to either social context or rank. Finally, we explored how the specific characteristics of the research context impacted on SDBs; namely, social context, reward contingency, and visual access to keepers. SDBs increased only when visual access to keepers was restricted, suggesting that visual contact reduced uncertainty in novel training contexts. Overall, the introduction of a cognitive research program did not compromise welfare, and the chimpanzees' repeated interest and willingness to participate suggests that the research was enriching.

Cognitive enrichment and welfare: Current approaches and future directions

“…Yamanashi and Hayashi (2011) reported that laboratory-housed chimpanzees participating in cognitive research (using CGTs) had comparable levels of foraging/feeding and resting to wild chimpanzees, and also spent significantly longer foraging/feeding than non-experimental chimpanzees at the same facility. Herrelko, Vick, and Buchanan-Smith (2012) found that, during the introduction of a new cognitive testing program (using CGTs) to zoo chimpanzees, SDBs increased when visual access to keepers was restricted, but not when the task changed in nature (i.e., level of difficulty).…”

“…Similarly, Clark and Smith (2013) found that there a disparity in device use within a mixed group of six zoo chimpanzees; two males were "high users" whereas the eldest female contacted the device (a pipe maze) a negligible amount, even though three copies of the device were made available to prevent task monopolization. In great apes, motivation to participate in cognitive tasks has been linked to various personality "traits" such as boldness (Herrelko et al, 2012).…”

Chimpanzee intellect: personality, performance and motivation with touchscreen tasks

“…Some of these traits describe individual differences in interest and engagement, but associations with performance on cognitive tasks have been weak. Chimpanzees' interest in a touchscreen task was associated with Openness [19], as was interest in puzzle box tasks [20]. Capuchin monkey participation in two spatial cognition tasks was correlated with Openness, but while performance on the first task was also correlated with Openness, performance on both was negatively correlated with Assertiveness [14].…”

Studying primate personality in zoos: implications for the management, welfare and conservation of great apes

“…Chimpanzees rated higher on Openness are more willing to participate in research studies (Herrelko et al, 2012). Furthermore, those rated higher on Neuroticism performed more self-directed behaviours during the study (Herrelko et al, 2012).…”

“…Chimpanzees rated higher on Openness are more willing to participate in research studies (Herrelko et al, 2012). Furthermore, those rated higher on Neuroticism performed more self-directed behaviours during the study (Herrelko et al, 2012). This has implications for animal management, where animals rated higher on Openness could be chosen first for training, which may provide the more reluctant animals with positive role models.…”