Tailored Enrichment Strategies and Stereotypic Behavior in Captive Individually Housed Macaques (Macaca spp.)

Quality of Life Assessment: The Value of Longitudinal Data in Making the End-of-Life Care Decision for a Macaque (Macaca Silenus/Macaca Nemestrina)

Assessing quality of life in animals is an art as much as a science. Despite the use of questionnaires and keeper reports which consider several aspects of well-being, the process often remains subjective. Keepers have unique insights, and anecdotal observations can be enhanced with objective data. We combined the art and science of assessments in this study on a geriatric macaque (1.0 lion-tailed/pig-tailed (Macaca silenus/macaca nemestrina) hybrid), using historic data to inform management decisions. Following the unexpected death of his cage mate, his activity and engagement with keepers decreased, and new concerning behaviors presented. While the zoo worked to identify new social opportunities, we used these data to develop a plan to improve his quality of life (e.g., increase training sessions, enrichment, social interactions). After intense implementation, we saw a significant increase in activity level and engagement with keepers; the frequency of unexpected behaviors suggesting a lower quality of life, however, increased over time. Our data allowed us to objectively compare changes in behavior, enabling the zoo to make the most informed animal management decision possible. [Figure: see text].

Stereotypic behaviors are associated with physiology and immunity differences in long-term confined sows

Pregnant sows in the confined environment have poor welfare and frequently perform stereotypic behaviors. In order to clarify whether highly stereotypic behavior is a sign of increased stress and successfully contributes to coping with or adaptation to adverse environment, fifty pregnant sows (Large White × Landrace) housed in stalls were selected to observe behaviors and analyze physiological parameters [cortisol, major acute phase protein (Pig-MAP) and C-reactive protein (CRP)], and immunological parameters [immunoglobin A (IgA), immunoglobin G (IgG), interleukin 6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ)] in early, middle and late gestation (27th, 62nd and 91st day). A repeated-measures analysis and Friedman test was performed to analyze the differences of behaviors and physiological and immunological parameters. The results showed that lateral lying behavior increased significantly with the progress of sows' gestation, while standing and ventral lying behaviors significantly decreased (p < 0.05). Sham-chewing, bar-biting, trough-biting and rooting behaviors significantly reduced (p < 0.05). Furthermore, there was no significant difference in physiological and immune levels in different gestational periods (p > 0.05). The results also indicated that sham-chewing behavior was positively correlated with serum cortisol, IL-6, IL-10, and negatively correlated with serum IFN-γ in each gestational period (p < 0.05). Trough-biting behavior was positively correlated with serum TNF-α in middle and late gestation (p < 0.05). Rooting behavior was positively correlated with serum IgG in each gestational period, and positively correlated with serum Pig-MAP, IL-6, and IL-10 in middle and late gestation (p < 0.05). In conclusion, the sows with a high incidence of stereotypic behaviors tried to improve stress and humoral immunity to cope with the confined environment, and long-term confined sows might be in a chronic stress state.

Effects of Positive Reinforcement Training and Novel Object Exposure on Salivary Cortisol Levels under Consideration of Individual Variation in Captive African Elephants (Loxodonta africana)

Simple Summary

Regular training for medical or enrichment purposes and the provision of environmental enrichment, such as varied feeding schedules and novel objects, are part of the management of African elephants in zoos. The present study aimed to find out whether training and enrichment in the form of a novel object induced physiological changes in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) before and after training and the exposure to a novel object for the analysis of cortisol and as a measure of stress and arousal. We found high salivary cortisol levels before and low levels after training. A novel object, in contrast, moderately increased the salivary cortisol levels. Moreover, males and young elephants showed lower salivary cortisol levels than females and old elephants, respectively. The zoo, handling method (free vs. protected contact to keepers), reproductive and social status, however, did not influence the salivary cortisol levels of the animals studied. We conclude that the relatively high cortisol values before training could be due to anticipation of the training event. A novel object, in contrast, may have evoked arousal, which led to the observed cortisol increase. In addition, understanding why animals differ in stress responses will help to manage stress in zoo elephants with the goal of ensuring their welfare.

Abstract

Dealing with potential stress in species that have high husbandry requirements, such as elephants, is a challenge for zoos. The objective of the present study was to determine whether positive reinforcement training (PRT) and exposure to a novel object (NOV) for enrichment induced a salivary cortisol response indicative of activation of the hypothalamic–pituitary–adrenal (HPA) axis and which factors determine individual variation in this regard in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) for the analysis of cortisol (SACort) before and up to 60 min (in 10–15 min intervals) after the onset of PRT (three repeats) or NOV (nine repeats), which lasted 10 min. There was considerable individual variation in SACort in response to PRT or NOV. Using mixed models, we were able to control these and to reveal that PRT was associated with high SACort before and relatively low SACort after PRT, while NOV induced a moderate SACort increase. The individual differences in SACort were related to age and sex (NOV), while the effects of zoo, handling method (free vs. protected contact) and reproductive and social status were variable. We conclude that positive affective states, such as anticipation or arousal, should be taken into account when interpreting the differences in the SACort responses between PRT and NOV. In addition, understanding the individuality of stress will support management decisions aimed at promoting captive elephant welfare.

A naturalistic environment to study visual cognition in unrestrained monkeys

Macaque monkeys are widely used to study vision. In the traditional approach, monkeys are brought into a lab to perform visual tasks while they are restrained to obtain stable eye tracking and neural recordings. Here, we describe a novel environment to study visual cognition in a more natural setting as well as other natural and social behaviors. We designed a naturalistic environment with an integrated touchscreen workstation that enables high-quality eye tracking in unrestrained monkeys. We used this environment to train monkeys on a challenging same-different task. We also show that this environment can reveal interesting novel social behaviors. As proof of concept, we show that two naive monkeys were able to learn this complex task through a combination of socially observing trained monkeys and solo trial-and-error. We propose that such naturalistic environments can be used to rigorously study visual cognition as well as other natural and social behaviors in freely moving monkeys.

Evaluation of an enrichment programme for a colony of long-tailed macaques (Macaca fascicularis) in a rescue centre

Long-tailed macaques are highly social primates that are commonly used in biomedical research as animal models. The aim of this study was to evaluate the effects of different kinds of enrichment on the behaviour and faecal cortisol metabolite (FCM) level in a colony of ex-laboratory long-tailed macaques during a programme of rehabilitation. The research was carried out in three periods, divided into two sessions each. Every period was composed of one control session (SC) and one session characterised by one type of enrichment: feeding enrichment (FE), manipulative enrichment (ME), and the last session during which manipulative and feeding enrichment were provided every day but in a mixed way (MIX). The results showed that manipulative and mixed enrichments caused positive changes to the activity budget of the colony, with a decrease in abnormal behaviour rates and an increase in play compared with control sessions. The rate of affiliative behaviours and low rate of aggression were probably because the group was composed mostly of females and it was stable, with a well-defined hierarchy. The research underlines the importance of a well-studied enrichment programme for the welfare of captive animals, which should exploit species-specific motivations.

Effects of personality and rearing-history on the welfare of captive Asiatic lions (Panthera leo persica)

Background

The long-term success of ex-situ conservation programmes depends on species-appropriate husbandry and enrichment practices complemented by an accurate welfare assessment protocol. Zoos and conservation breeding programmes should employ a bottom-up approach to account for intraspecific variations in measures of animal welfare. We studied 35 (14:21) captive Asiatic lions in Sakkarbaug Zoological Garden, Junagadh, India to understand the implications of individual variations on welfare measures. We categorized the subjects based on personality traits (bold or shy), rearing history (wild-rescued or captive-raised), sex, and social-grouping. We explored the association of these categorical variables on welfare indices such as behavioural diversity, latency to approach novel objects, enclosure usage and aberrant repetitive behaviours. Further, we assessed the inter-relationships between different behavioural measures of welfare.

Results

Our results show that intraspecific variations based on rearing-history and personality traits are significantly associated with the welfare states of captive Asiatic lions. Asiatic lions with bold personality traits (M = 0.50, SD = 0.12, N = 21) and those raised in captivity (M = 0.47, SD = 0.12, N = 16) used enclosure space more homogenously compared to shy (M = 0.71, SD = 0.15, N = 14) and wild-rescued (M = 0.67, SD = 0.15, N = 19) animals. Behaviour diversity was significantly higher in captive-raised (M = 1.26, SD = 0.3, N = 16) and bold (M = 1.23, SD = 0.26, N = 21) subjects compared to wild-rescued (M = 0.83, SD = 0.35, N = 19) and shy (M = 0.73, SD = 0.34, N = 14) individuals. Aberrant repetitive behaviours (stereotypy) were significantly lower in bold (M = 7.01, SD = 4, N = 21) and captive-raised (M = 7.74, SD = 5.3) individuals compared to wild-rescued (M = 13.12, SD = 6.25, N = 19) and shy (M = 16.13, SD = 5.4, N = 16) lions. Sex and social-grouping of subjects did not show significant associations with behavioural welfare indices. Interestingly, behaviour diversity was reliably predicted by the enclosure usage patterns and aberrant repetitive behaviours displayed by subjects.

Discussion

Our findings underline the importance of individual-centric, behaviour-based, and multi-dimensional welfare assessment approaches in ex-situ conservation programmes. The results suggest that behavioural welfare indices complemented with individual variations can explain inter-individual differences in behavioural welfare measure outcomes of Asiatic lions. These findings also provide zoo managers with a non-invasive tool to reliably assess and improve husbandry practices for Asiatic lions. Understanding the unique welfare requirement of individuals in captivity will be crucial for the survival of the species.

Nonhuman primate welfare: Can there be a relationship between personality, lateralization and physiological indicators?

Measuring personality is being used to improved nonhuman primate welfare. To expand its use, it is important to identify traits that are shared between species and that measures are reliable, easy to use and less time consuming. Combining personality and other indicators strong validation of the results can be obtained. In the present study, we sought to determine if there is a link between physiological stress response (fecal cortisol metabolites), personality (ratings made by animal keepers and reaction to novel objects) and lateralization of the brain (hand preferences) on eight species of nonhuman primates: Callithrix jacchus, Callithrix geoffroyi, Cebuella Pygmaea, Saguinus imperator, Saguinus oedipus, Leontopithecus rosalia, Pithecia pithecia and Nycticebus pygmaeus. Personality assessments achieved good levels of interrater reliability and revealed three components of personality in our sample: fearfulness, activeness and aggressiveness. More exploratory individuals were more active, aggressive and showed higher cortisol metabolite levels. Right-handed subjects inspected novel objects sooner and the strength of the lateralization was linked with individual stress and the aggressiveness component. Our results highlight that there is a relation between personality, lateralization and physiological indicators in nonhuman primates, but although some aspects can be generalized across species and/or sexes others are species/sex dependent.

Effects of housing conditions on behaviors and biochemical parameters in juvenile cynomolgus monkeys (Macaca fascicularis)

To investigate the effects of environmental enrichment on laboratory monkeys, we studied behavioral and physiological differences following changes in housing conditions. Ten male and female juvenile cynomolgus monkeys were first housed in pairs for 8 weeks after quarantine/acclimatization (singly housed) and subsequently housed alone for the next 8 weeks. Monkeys were subjected to evaluations of body weight gain, stereotypic or affiliative behaviors, cortisol, 4-ethylphenyl sulfate (4EPS) and catecholamine concentrations in biological samples, and blood chemistry tests under both housing conditions. Under paired housing, the stereotypic behavioral score decreased in both sexes, and the affiliative behavioral score increased in males and showed an increasing trend in females. Under single housing, the stereotypic score increased in both sexes, and the affiliative score decreased in males. Paired housing decreased serum calcium and urine cortisol concentrations in both sexes and decreased plasma cortisol in males and plasma 4EPS concentrations in females. The stereotypic score was positively correlated with serum calcium, plasma and urine cortisol, and plasma 4EPS concentration and negatively correlated with the affiliative score. The feces painting score, affiliative score, and plasma cortisol and serum calcium concentrations showed sex differences, suggesting differences in responsiveness to environmental changes between males and females. In conclusion, paired housing improved behavioral abnormalities in juvenile cynomolgus monkeys, suggesting that it may be an effective environmental enrichment paradigm. Calcium, cortisol, and 4EPS concentrations in biological samples may be useful indices for evaluating the effects of environmental enrichment.