Video preference assessment and behavioral management of single-caged Japanese macaques (Macaca fuscata) by movie presentation

No immediate attentional bias towards or choice bias for male secondary sexual characteristics in Bornean orang-utans (Pongo pygmaeus)

Primate faces provide information about a range of variant and invariant traits, including some that are relevant for mate choice. For example, faces of males may convey information about their health or genetic quality through symmetry or facial masculinity. Because perceiving and processing such information may have bearing on the reproductive success of an individual, cognitive systems are expected to be sensitive to facial cues of mate quality. However, few studies have investigated this topic in non-human primate species. Orang-utans are an interesting species to test mate-relevant cognitive biases, because they are characterised by male bimaturism: some adult males are fully developed and bear conspicuous flanges on the side of their face, while other males look relatively similar to females. Here, we describe two non-invasive computerised experiments with Bornean orang-utans (Pongo pygmaeus), testing (i) immediate attention towards large flanges and symmetrical faces using a dot-probe task (N = 3 individuals; 2F) and (ii) choice bias for pictures of flanged males over unflanged males using a preference test (N = 6 individuals; 4F). In contrast with our expectations, we found no immediate attentional bias towards either large flanges or symmetrical faces. In addition, individuals did not show a choice bias for stimuli of flanged males. We did find exploratory evidence for a colour bias and energy efficiency trade-offs in the preference task. We discuss our null results and exploratory results in the context of the evolutionary history of Bornean orang-utans, and provide suggestions for a more biocentric approach to the study of orang-utan cognition.

Owner-implemented paired-stimulus food preference assessments for companion dogs

Behavioral interventions for animals typically require the inclusion of programmed reinforcers. Although pet owners and human caregivers can often identify items that the animal will consume, preference assessments can more accurately determine relative preference rankings between various stimuli, which is important given that higher preferred items tend to function as more effective reinforcers than lower preferred items. Preference assessments have been developed to identify rankings for a variety of stimuli across species, including the domesticated dog (Canis lupus familiaris). However, previous preference assessments for dogs were developed for laboratory use and could be challenging for dog owners to perform alone. The purpose of this study was to modify existing dog preference assessment methods to produce a valid and feasible preference assessment for dog owners. Results suggest that the preference assessment identified preference rankings for individual dogs. Owners were able to implement the protocol with high integrity and found the protocol acceptable.

Applied behavior analysis and the zoo: Forthman and Ogden (1992) thirty years later

The field of applied behavior analysis has been directly involved in both research and applications of behavioral principles to improve the lives of captive zoo animals. Thirty years ago, Forthman and Ogden (1992) wrote one of the first papers documenting some of these efforts. Since that time, considerable work has been done using behavioral principles and procedures to guide zoo welfare efforts. The current paper reexamines and updates Forthman and Ogden's original points, with attention to the 5 categories they detailed: (a) promotion of species-typical behavior, (b) reintroduction and repatriation of endangered species, (c) animal handling, (d) pest control, and (e) animal performances. In addition, we outline 3 current and future directions for behavior analytic endeavors: (a) experimental analyses of behavior and the zoo, (b) applied behavior analysis and the zoo, and (c) single-case designs and the zoo. The goal is to provide a framework that can guide future behavioral research in zoos, as well as create applications based on these empirical evaluations.

Are conspecific social videos rewarding to chimpanzees (Pan troglodytes)? A test of the social motivation theory

Many claim that social stimuli are rewarding to primates, but few, if any, studies have explicitly demonstrated their reward value. Here, we examined whether chimpanzees would produce overt responses for the opportunity to view conspecific social, compared to dynamic (video: Experiment 1) and static (picture: Experiment 2) control content. We also explored the relationships between variation in social reward and social behavior and cognition. We provided captive chimpanzees with access to a touchscreen during four, one-hour sessions (two 'conspecific social' and two 'control'). The sessions consisted of ten, 15-second videos (or pictures in Experiment 2) of either chimpanzees engaging in a variety of behaviors (social condition) or vehicles, humans, or other animals engaged in some activity (control condition). For each chimpanzee, we recorded the number of responses to the touchscreen and the frequency of watching the stimuli. Independent t-tests revealed no sex or rearing differences in touching and watching the social or control videos (p>0.05). Repeated measures ANOVAs showed chimpanzees touched and watched the screen significantly more often during the social compared to control video sessions. Furthermore, although chimpanzees did not touch the screen more often during social than control picture sessions in Experiment 2, they did watch the screen more often. Additionally, chimpanzees that previously performed better on a task of social cognition and engaged in more affiliative behavior watched a higher percentage of social videos during the touchscreen task. These results are consistent with the social motivation theory, and indicate social stimuli are intrinsically rewarding, as chimpanzees made more overt responses for the opportunity to view conspecific social, compared to control, content.

The relationship between personality, season, and wounding receipt in zoo-housed Japanese macaques (Macaca fuscata): A multi-institutional study

It is important to those managing Japanese macaques (Macaca fuscata) in captive settings to understand predictors of wounding. While studies have demonstrated that season (breeding or nonbreeding) and sex predict rates of wounding received by zoo-housed Japanese macaques, we investigated whether individual differences in personality ratings also might explain some of the observed interindividual variance in wounding. Such patterns were previously observed in rhesus macaques (M. mulatta), such that individuals rated higher on Anxiety and Confidence received greater wounding. Here, we collected wounding data over 24 months on 48 Japanese macaques from eight AZA-accredited zoos. Each macaque was also rated by keepers using a 26-item personality questionnaire. Principle components analysis of these ratings revealed four personality components: Openness, Friendliness, Dominance, and Anxiety/Reactivity. The model with the best fit revealed an interaction effect between season (breeding vs. nonbreeding) and the personality component Friendliness, such that individuals rated higher on Friendliness incurred fewer wounds in the nonbreeding season. The second-best model revealed both a main effect of the season as well as an interaction effect between season and Openness, such that macaques rated higher in Openness received more wounds in the nonbreeding season than those rated lower in Openness. Thus, as with rhesus macaques, personality mediated wounding receipt rate in Japanese macaques, although different personality components explained interindividual variance in wounding for these two species. These differences likely reflect species differences in behavior and personality structure, as well as the influence of differing management practices, highlighting the importance of species-specific approaches for captive primate care and welfare. This study provides further support for understanding primate personality to create individualized strategies for their care.

Exploring How White-Faced Sakis Control Digital Visual Enrichment Systems

Simple Summary

Many zoo-housed primates use visual computer systems for enrichment but little is known about how monkeys would choose to control these devices. Here we investigate what visual enrichment white-faced saki monkeys would trigger and what effect these videos have on their behaviour. To study this, we built an interactive screen device that would trigger visual stimuli and track the sakis’ interactions when using the system. Over several weeks, we found that the sakis would trigger underwater and worm videos significantly more than animal, abstract art and forest videos, and the control condition of no-stimuli. Further, the sakis triggered the animal video significantly less often over all other conditions. Yet, viewing their interactions over time, the sakis’ usage of the device followed a bell curve, suggesting novelty and habituation factors. As such, it is unknown if the stumli or devices novelty and habituation caused the changes in the sakis interactions over time. These results also indicated that the different visual stimuli conditions significantly reduced the sakis’ scratching behaviour with the visual stimuli conditions compared to the control condition. Further, the usage of visual stimuli did not increase the sakis’ looking at and sitting in front of the screen behaviours. These results highlight problems in defining interactivity and screen usage with monkeys and screens from looking behaviours and proximity alone.

Abstract

Computer-enabled screen systems containing visual elements have long been employed with captive primates for assessing preference, reactions and for husbandry reasons. These screen systems typically play visual enrichment to primates without them choosing to trigger the system and without their consent. Yet, what videos primates, especially monkeys, would prefer to watch of their own volition and how to design computers and methods that allow choice is an open question. In this study, we designed and tested, over several weeks, an enrichment system that facilitates white-faced saki monkeys to trigger different visual stimuli in their regular zoo habitat while automatically logging and recording their interaction. By analysing this data, we show that the sakis triggered underwater and worm videos over the forest, abstract art, and animal videos, and a control condition of no-stimuli. We also note that the sakis used the device significantly less when playing animal videos compared to other conditions. Yet, plotting the data over time revealed an engagement bell curve suggesting confounding factors of novelty and habituation. As such, it is unknown if the stimuli or device usage curve caused the changes in the sakis interactions over time. Looking at the sakis’ behaviours and working with zoo personnel, we noted that the stimuli conditions resulted in significantly decreasing the sakis’ scratching behaviour. For the research community, this study builds on methods that allow animals to control computers in a zoo environment highlighting problems in quantifying animal interactions with computer devices.

Visual stimulation-induced mild stress enhances cognitive behavior in cynomolgus monkey

Cortisol is a well-known endogenous glucocorticoid that serves as a stress indicator. It is normally released under stressful condition to warn about imminent danger and thus is critical for survival of the species. However, it is unclear how cortisol relates to cognitive process under physiological condition in high-order primates such as non-human primates (NHP). Here, we report that a slight but significant increase in blood cortisol level by mild stress is positively correlated with the cognitive function in cynomolgus monkey. We stimulated 3 groups of monkeys by viewing consecutive series of pictures of monkeys, pictures of humans, or animation still pictures. We first found that the blood cortisol level was significantly higher during the stimulation session and returned to normal after stimulation session. Among the three types of pictures, the monkeys which were stimulated with monkey pictures showed the most significant increase in cortisol level during stimulation. Furthermore, the monkeys showed significantly enhanced manipulation, suggesting that cortisol affected cognitive processes. Overall, our study demonstrates that visual stimulation both increases blood cortisol and enhances manipulating behavior. Therefore, unlike the common notion that cortisol is a stress indicator, our data supports that a mild increase of cortisol enhances cognition in NHP.

Environmental Enrichment in the 21st Century

More than a quarter of a century has elapsed since the Animal Welfare Act mandated that research facilities develop and follow a plan to promote the psychological well-being of captive primates. Since passage of this law, considerable effort and resources have been directed to designing environmental enrichment strategies in an effort to improve animal welfare. These plans typically consist of environmental enrichment and socialization efforts. While environmental enhancement has undergone a great deal of improvement in the past 25 years, it should be viewed as a continual work in progress, which takes advantage of emergent and future technologies. In this review, we discuss the objectives of the environmental enhancement plan along with relevant outcome measures, as well as ongoing challenges, costs, and benefits. We then review various enrichment strategies and assess their efficacy in meeting goals and objectives. Finally, we look forward to consider what the future might hold for environmental enrichment of nonhuman primates used in research.

The use of preferred social stimuli as rewards for rhesus macaques in behavioural neuroscience

Macaques are often motivated to perform in neuroscientific experiments by implementing fluid restriction protocols. Daily access to water is controlled and the monkeys are rewarded with droplets of fluid for performing correct trials in the laboratory. Although these protocols are widely used and highly effective, it is important from a 3Rs perspective to investigate refinements that may help to lessen the severity of the fluid restriction applied. We assessed the use of social stimuli (images of conspecifics) as rewards for four rhesus macaques performing simple cognitive tasks. We found that individual preferences for images of male faces, female perinea and control stimuli could be identified in each monkey. However, using preferred images did not translate into effective motivators on a trial-by-trial basis: animals preferred fluid rewards, even when fluid restriction was relaxed. There was no difference in the monkeys' performance of a task when using greyscale versus colour images. Based on our findings, we cannot recommend the use of social stimuli, in this form, as a refinement to current fluid restriction protocols. We discuss the potential alternatives and possibilities for future research.