Using Behavioral Instability to Investigate Behavioral Reaction Norms in Captive Animals: Theoretical Implications and Future Perspectives

Abstract

Behavioral instability is a concept used for indicating environmental stress based on behavioral traits. This study investigates the possibility of using behavioral instability as a tool for assessing behavioral reaction norms in captive animals. The understanding of personality in captive animals can be a useful tool in the development of enrichment programs in order to improve animal welfare. In this study, a case study examined how olfactory stimuli affected the behavior of two polar bears Ursus maritimus in captivity. Using continuous focal sampling throughout the day, it was found that for many behaviors, the individuals responded differently to stimuli, indicating that there was a difference in behavioral reaction norms. This is shown using multiple approaches. One approach used traditional methods for behavioral analyses, and the other approach used the concept of behavioral instability as a new quantitative method. This study demonstrates the utility of behavioral instability as a new quantitative method for investigating behavioral reaction norms, expanding the possibility of comparing behavioral responses between species. Moreover, it is shown that outliers—that cause asymmetric distributions—should not be removed in behavioral analysis, without careful consideration. In conclusion, the theoretical implications and future perspectives of behavioral instability are discussed.

The Social and Self-Directed Behaviours of Captive Golden Lion Tamarins (<em>Leontopithecus rosalia</em>) within a Pair with a Sick Individual

“…According to an earlier study, some marmosets are known to display repetitive or purposeless (Linder, et al, 2020) behaviour, which can be expressed in response to sub-optimal physical and/or mental state. Stereotypical behaviours might for instance be carried out to reduce the psychological stress experienced by the marmoset (Kaplan & Rogers, 2012).…”

“…Captive family troops of marmosets, whose composition would not be seen naturally occurring, might be more susceptible to display abnormal behaviours (Linder, et al, 2020) (Morgan & Tromborg, 2007), and this might be factor in the unusual (Snyder, 1974) proportion of time allocated to doing abnormal and stereotyped behaviours (Lutz, et al, 2022) in both individuals.…”

“…These behaviours can include the deficient acquisition of essential survival skills (Sanders & Fernandez, 2020), or detrimental and unnatural stereotypical behaviour, which is often observed in captive animals (Hosey, 2005) (Gottlieb, et al, 2013). Stereotypical behaviours are atypical and repetitive behaviours with no apparent purpose, such as auto-aggression and autoerotism (Gottlieb, et al, 2013) (Lutz, et al, 2022) (Linder, et al, 2020). These behavioural patterns usually indicate that an animals' psychological welfare is sub-optimal (Lutz, et al, 2022) (Mason & Rushen, 2006) (Linder, et al, 2020).…”

“…Stereotypical behaviours are atypical and repetitive behaviours with no apparent purpose, such as auto-aggression and autoerotism (Gottlieb, et al, 2013) (Lutz, et al, 2022) (Linder, et al, 2020). These behavioural patterns usually indicate that an animals' psychological welfare is sub-optimal (Lutz, et al, 2022) (Mason & Rushen, 2006) (Linder, et al, 2020). Stereotypical behaviour is often accentuated by insufficient stimuli in the enclosure or may occur as a stress response to the environment or other individuals in the social hierarchy (Lutz, et al, 2022) (Redshaw & Mallinson, 1991) (Carlstead & Shepherdson, 2000).…”

“…Zoos generally run a higher risk of having an environment that is not optimally suited for the animal (Hosey, 2005) (Sanders & Fernandez, 2020), although modern zoos try to negate this issue to assure the welfare of the animals (Hosey, 2005). Zoos might provide climate control in the enclosures, variation in stimuli and attempt to promote natural behaviours seen in wild GLT, by for instance promoting troop-compositions which could exist in a natural environment (Hosey, 2005) (Snyder, 1974) (Stolwijk, 2013), playing (Snyder, 1974) (Lutz, et al, 2022), self-and allogrooming (Snyder, 1974), resting during the day and bedding down together in dens at lights out (Snyder, 1974), via enrichment programs (Linder, et al, 2020).…”