Positive Reinforcement Training for a Trunk Wash in Nepal's Working Elephants: Demonstrating Alternatives to Traditional Elephant Training Techniques

Many trainers of animals in the zoo now rely on positive reinforcement training to teach animals to voluntarily participate in husbandry and veterinary procedures in an effort to improve behavioral reliability, captive management, and welfare. However, captive elephant handlers in Nepal still rely heavily on punishment- and aversion-based methods. The aim of this project was to determine the effectiveness of secondary positive reinforcement (SPR) in training free-contact elephants in Nepal to voluntarily participate in a trunk wash for the purpose of tuberculosis testing. Five female elephants, 4 juveniles and 1 adult, were enrolled in the project. Data were collected in the form of minutes of training, number of offers made for each training task, and success rate for each task in performance tests. Four out of 5 elephants, all juveniles, successfully learned the trunk wash in 35 sessions or fewer, with each session lasting a mean duration of 12 min. The elephants' performance improved from a mean success rate of 39.0% to 89.3% during the course of the training. This study proves that it is feasible to efficiently train juvenile, free-contact, traditionally trained elephants in Nepal to voluntarily and reliably participate in a trunk wash using only SPR techniques.     

Conditioned exercise method for use with nonhuman primates

The objective of this study was to demonstrate the feasibility of using appetitive methods to train adult male olive baboons (Papio cynocephalus anubis), who were socially housed and fitted with indwelling catheter/ transducer systems, to exercise on an inclined, motorized, moving treadmill. All subjects were first trained to walk on a motorized treadmill for 30 min at a speed of approximately 1.6 km/hr on a 0 grade. Upon completion of initial exercise training, six animals were assigned to a low exercise group (LOW), six were assigned to a moderate exercise group (MOD), and six were assigned to a sedentary control group (SED). The LOW group exercised 30 min per day on an elevated treadmill, the MOD group exercised 60 min per day on an elevated treadmill and the SED group did not perform any treadmill exercise. The 12 animals comprising the LOW and MOD groups were exercised 4 days per week and their performance was increased over a subsequent 30-week experimental period. We gradually increased speed and grade demands over several weeks and produced an animal model capable of traveling at speeds up to 5.5 km/hr on a 22% grade and distances up to 3,353 m horizontally and 549 m vertically in a 1-hr session. © 1992 Wiley-Liss, Inc.     

Positive Reinforcement Training in Squirrel Monkeys Using Clicker Training

Nonhuman primates in research environments experience regular stressors that have the potential to alter physiology and brain function, which in turn can confound some types of research studies. Operant conditioning techniques such as positive reinforcement training (PRT), which teaches animals to voluntarily perform desired behaviors, can be applied to improve behavior and reactivity. PRT has been used to train rhesus macaques, marmosets, and several other nonhuman primate species. To our knowledge, the method has yet to be used to train squirrel monkeys to perform complex tasks. Accordingly, we sought to establish whether PRT, utilizing a hand‐box clicker (which emits a click sound that acts as the conditioned reinforcer), could be used to train adult male squirrel monkeys (Saimiri boliviensis, N = 14). We developed and implemented a training regimen to elicit voluntary participation in routine husbandry, animal transport, and injection procedures. Our secondary goal was to quantify the training time needed to achieve positive results. Squirrel monkeys readily learned the connection between the conditioned reinforcer (the clicker) and the positive reinforcer (food). They rapidly developed proficiency on four tasks of increasing difficulty: target touching, hand sitting, restraint training, and injection training. All subjects mastered target touching behavior within 2 weeks. Ten of 14 subjects (71%) mastered all tasks in 59.2 ± 2.6 days (range: 50–70 days). In trained subjects, it now takes about 1.25 min per monkey to weigh and administer an intramuscular injection, one‐third of the time it took before training. From these data, we conclude that clicker box PRT can be successfully learned by a majority of squirrel monkeys within 2 months and that trained subjects can be managed more efficiently. These findings warrant future studies to determine whether PRT may be useful in reducing stress‐induced experimental confounds in studies involving squirrel monkeys. Am. J. Primatol. 74:712–720, 2012. © 2012 Wiley Periodicals, Inc.     

Training of laboratory-housed non-human primates in the UK

Abstract

Laboratory-housed non-human primates may experience a range of potential stressors, including physical and chemical restraint, venepuncture, injection, catching and cage-change. Training them to co-operate, using positive reinforcement techniques, is one means of significantly reducing the adverse impact of such procedures upon them and, therefore, is a refinement. Furthermore, the additional time that staff spend with the primates, and the need for individual recognition and close observation of animal behavior, mean that the trainer develops a relationship with each individual animal which can be beneficial for animal welfare (e.g., by reducing the occurrence of abnormal behavior and fear of humans). We surveyed use of training in thirteen UK establishments using and breeding primates, utilizing a mixed-mode questionnaire. The survey demonstrated that there is widespread awareness of training as a refinement and appreciation of its diverse benefits, but training is not used as widely or as fully as it might be. This is largely due to real constraints (principally staff and time and a lack of confidence in ability to train), and perceived constraints (such as a supposed lack of information on how to train and assessment of the benefits, and an overestimation of the time investment needed). There is also considerable variation between establishments in the purposes of training and techniques used, with a reliance on negative reinforcement in three. We conclude that there is considerable scope for refinement of common scientific, veterinary and husbandry procedures, and refer to some resources designed to help establishments take action (e.g., Prescott and Buchanan-Smith 2003).     

Technical note: Urine collection from vervet monkeys by instrumental conditioning

Gang-caged adult male vervet monkeys were trained to urinate on demand into a plastic beaker by positive reinforcement (peanut rewards). The animals were not separated from their social group during training or sampling.     

Positive reinforcement training to enhance the voluntary movement of group-housed chimpanzees within their enclosures

Positive reinforcement techniques were applied to train groups of chimpanzees to move voluntarily into the indoor portions of their enclosures at the request of trainers and to be briefly restricted to those areas. Subjects were 66 members of eight social groups, including 44 adults (14 males, 30 females), and 22 immatures (eight males, 14 females). Performance of individual animals was recorded during four experimental phases of the project: baseline, initial training, maintenance of reliable performance, and transfer of responsibility for training from the original trainers to others on staff. A mean of 16.1 training sessions was required to reach reliable performance, defined as the subjects' complying with 90% of the requests to move indoors. Analyses of variance indicated that chimpanzee compliance was significantly increased after training. Females required significantly fewer training sessions to reach reliable performance than did males. Adult males showed the lowest level of compliance in each experimental phase. Overall, compliance was not affected by the transfer of responsibility for the procedure from the original trainer to other staff, although there was evidence of a temporary and small decrement in performance immediately following transfer. These findings indicate that training can improve the voluntary movement of captive chimpanzees. They also demonstrate that animal training can be objectively evaluated using systematic study design, data collection, and statistical analysis of data. Zoo Biol 17:333–341, 1998. © 1998 Wiley-Liss, Inc.     

Temperament correlates with training success in adult rhesus macaques

In recent years there has been a marked increase in awareness of issues involving the psychological well-being of nonhuman primates (NHPs) used in biomedical research. As a result, many facilities are starting to train primates to voluntarily cooperate with veterinary, husbandry, and research procedures, such as remaining still for blood draws or injections. Such training generally reduces the stress associated with these procedures, resulting in calmer animals and, ultimately, better research models. However, such training requires great investments in time, and there can be vast individual differences in training success. Some animals learn tasks quickly, while others make slower progress in training. In this study, we examined whether temperament, as measured by response to a novel food object, correlated with the amount of time it took to train 20 adult female rhesus macaques to perform a simple task. The monkeys were categorized as "exploratory" (i.e., inspected a novel object placed in the home cage within 10 sec), "moderate" (i.e., inspected the object within 10-180 sec), or "inhibited" (i.e., did not inspect the object within 3 min). We utilized positive reinforcement techniques to train the monkeys to touch a target (PVC pipe shaped like an elbow) hung on their cage. Temperament correlated with training success in this study (Pearson chi2=7.22, df=2, P=0.03). We easily trained over 75% of the animals that inspected the novel food (i.e., exploratory or moderate individuals) to touch the target. However, only 22% of the inhibited monkeys performed the task. By knowing which animals may not respond to conventional training methods, we may be able to develop alternate training techniques to address their specific needs. In addition, these results will allow us to screen monkeys to be assigned to research projects in which they will be trained, with the goal of obtaining the best candidates for those studies.     

Positive reinforcement training in rhesus macaques—training progress as a result of training frequency

Positive reinforcement training (PRT) efficiency was examined as a function of training frequency in 33 pair‐ or triple‐housed female rhesus macaques. The animals were trained three times a week, once a day or twice a day, using PRT and a clicker as a secondary reinforcer. All animals were trained on 30 sessions, with an average of 5 min per training session per animal. The behaviors, trained in succession, were Targeting (reliably touching and following a Target); Collaborating (dominant animals allowing subordinates to train while stationing); Box‐training (accepting being enclosed in a small compartment while responding to Target training) and initial Injection training. Fulfilled criteria for Targeting were obtained in 32/33 animals in a median of nine training sessions. Collaboration was obtained in 27/33 animals in a median of 15 training sessions. However, only four animals completed Box‐training during the 30 training sessions and started Injection training. When comparing training success in terms of number of training sessions, training twice a day was less efficient than the other two treatments. In terms of daily progress, our results suggest that from a management perspective, daily training is more conducive to quick training success than thrice weekly training. In addition, in this study no further advantages could be gained from training twice a day. Am. J. Primatol. 71:373–379, 2009. © 2009 Wiley‐Liss, Inc.     

EMG Biofeedback: The Effects of CRF, FR, VR, FI, and VI Schedules of Reinforcement on the Acquisition and Extinction of Increases in Forearm Muscle Tension

Biofeedback was used to increase forearm-muscle tension. Feedback was delivered under continuous reinforcement (CRF), variable interval (VI), fixed interval (FI), variable ratio (VR), and fixed ratio (FR) schedules of reinforcement when college students increased their muscle tension (electromyograph, EMG) above a high threshold. There were three daily sessions of feedback, and Session 3 was immediately followed by a session without feedback (extinction). The CRF schedule resulted in the highest EMG, closely followed by the FR and VR schedules, and the lowest EMG scores were produced by the FI and VI schedules. Similarly, the CRF schedule resulted in the greatest amount of time-above-threshold and the VI and FI schedules produced the lowest time-above-threshold. The highest response rates were generated by the FR schedule, followed by the VR schedule. The CRF schedule produced relatively low response rates, comparable to the rates under the VI and FI schedules. Some of the data are consistent with the partial-reinforcement-extinction effect. The present data suggest that different schedules of feedback should be considered in muscle-strengthening contexts such as during the rehabilitation of muscles following brain damage or peripheral nervous-system injury.     

Using training to moderate chimpanzee aggression during feeding

The effects of human and nonhuman primate interactions on the well-being of captive nonhuman primates have been studied less rigorously than other forms of environmental improvement. Human intervention might be used to moderate severe aggression of socially housed animals at feeding times, one of the most common behavioral management problems. In this study, positive reinforcement training techniques were applied to reduce a dominant male chimpanzee's aggression and chasing during meals. Verbal commands and food reinforcers were used to train him to sit and remain seated while other group members received and ate their share of produce. Observational data were collected recording all instances of agonism in the group during periods when meals were fed and during times when no meals were offered, both before and after the training was accomplished. Multivariate analysis of variance for repeated measures results indicated that the training program successfully reduced the group's incidence of displaying, submission, and aggression during feeding periods. This effect was specific to the times meals were fed; there was no generalized reduction in the group's agonism after the training. This study exemplifies the use of positive reinforcement techniques to modify chimpanzee social dynamics during a problematic situation and of observational data to evaluate quantitatively the behavioral effects of the training. Training can be employed to help solve behavioral management problems among socially housed animals, and it can help improve the psychological well-being of captive chimpanzees. © 1994 Wiley-Liss, Inc.     

Training to reliably obtain blood and urine samples from a diabetic chimpanzee (Pan troglodytes)

Positive reinforcement training techniques were used to gain the cooperation of a socially housed, 3-year-old, insulin-dependent diabetic chimpanzee (Pan troglodytes) in obtaining blood and urine samples for monitoring of glucose levels. A urine collection device, adaptable to many types of caging, allowed collection of urine from the diabetic subject as well as other trained, socially housed animals in their home cages. Four years after initial training, the diabetic subject continued to urinate into the container any time of the day or night, usually within 2 min of presentation of the cue, without removal from the home cage or separation from her companions. Blood samples were readily obtained from the subject by heel puncture or venipuncture. © 1996 Wiley-Liss, Inc.     

Manipulating the affiliative interactions of group-housed rhesus macaques using positive reinforcement training techniques.

Social housing, whether continuous, intermittent, or partial contact, typically provides many captive primates with opportunities to express affiliative behaviors, important components of the species-typical behavioral repertoire. Positive reinforcement training techniques have been successfully employed to shape many behaviors important for achieving primate husbandry goals. The present study was conducted to determine whether positive reinforcement training techniques could also be employed to alter levels of affiliative interactions among group-housed rhesus macaques. Twenty-eight female rhesus were divided into high (n = 14) and low (n = 14) affiliators based on a median split of the amount of time they spent affiliating during the baseline phase of the study. During the subsequent training phase, half of the low affiliators (n = 7) were trained to increase their time spent affiliating, and half of the high affiliators (n = 7) were trained to decrease their time spent affiliating. Trained subjects were observed both during and outside of training sessions. Low affiliators significantly increased the amount of time they spent affiliating, but only during nontraining sessions. High affiliators on the other hand, significantly decreased the amount of time they spent affiliating, but only during training sessions. These data suggest that positive reinforcement techniques can be used to alter the affiliative behavior patterns of group-housed, female rhesus monkeys, although the two subgroups of subjects responded differently to the training process. Low affiliators changed their overall behavioral repertoire, while high affiliators responded to the reinforcement contingencies of training, altering their proximity patterns but not their overall behavior patterns. Thus, positive reinforcement training can be used not only as a means to promote species-typical or beneficial behavior patterns, but also as an important experimental manipulation to facilitate systematic analyses of the effects of psychosocial factors on behavior and potentially even immunology.     

A Comparison of Positive Reinforcement Training Techniques in Owl and Squirrel Monkeys: Time Required to Train to Reliability

This study compared the physiological response to novel situations in sex-separated and sex-mixed groups of horses, as measured by heart rate (HR). The study evaluated the possibility of training horses in a mixed-sex system. The study included 41 Purebred Arabian 2½-year-olds during their first walk on an automated horse walker. Four groups, divided by manner of care and training, consisted of 10 colts and 10 fillies kept in separate stables and trained in separate male or female groups and 12 colts and 9 fillies kept in the same stable and trained together. The study measured HR when horses were at rest before exercise, while moving from stable to walker, during 30 min of exercise on walker, while moving from walker to stable, and at rest after exercise. Mean HR scores recorded from training on the walker were higher in sex-mixed groups. Results obtained while horses were moving from stable to walker, then from walker to stable, were significantly higher in the sex-mixed groups. The study did not recommend training young horses in sex-mixed groups.     

Species differences in adrenocortical activity of new world primates: Response to dexamethasone suppression

The effect of dexamethasone-induced alteration of adrenocortical activity was assessed in two species of New World primates: Saimiri sciureus and Callicebus moloch. Basal and stress levels of corticosteroids were determined following treatment with three doses of dexamethasone (0, 50, or 500 μg/kg). Saimiri showed substantially higher basal levels of corticosteroids than did Callicebus and a greater incremental corticosteroid response to physical restraint. Dexamethasone was found to reduce basal corticosteroids in both species, although this effect was greater for Callicebus than for Saimiri Moreover, the adrenocortical response to physical restraint was reduced by dexamethasone treatment in Callicebus but not in Saimiri. The pattern of results suggests that the species differ in the mechanisms mediating adrenocortical activity.     

Positive reinforcement training affects hematologic and serum chemistry values in captive chimpanzees (Pan troglodytes)

Positive reinforcement training (PRT) techniques have received considerable attention for their stress reduction potential in the behavioral management of captive nonhuman primates. However, few published empirical studies have provided physiological data to support this position. To address this issue, PRT techniques were used to train chimpanzees (Pan troglodytes) to voluntarily present a leg for an intramuscular (IM) injection of anesthetic. Hematology and serum chemistry profiles were collected from healthy chimpanzees (n=128) of both sexes and various ages during their routine annual physical examinations over a 7-year period. Specific variables potentially indicative of acute stress (i.e., total white blood cell (WBC) counts, absolute segmented neutrophils (SEG), glucose (GLU) levels, and hematocrit (HCT) levels) were analyzed to determine whether the method used to administer the anesthetic (voluntary present for injection vs. involuntary injection) affected the physiological parameters. Subjects that voluntarily presented for an anesthetic injection had significantly lower mean total WBC counts, SEG, and GLU levels than subjects that were involuntarily anesthetized by more traditional means. Within-subjects analyses revealed the same pattern of results. This is one of the first data sets to objectively demonstrate that PRT for voluntary presentation of IM injections of anesthetic can significantly affect some of the physiological measures correlated with stress responses to chemical restraint in captive chimpanzees.     

Analysis of training-induced changes in ethyl acetate odor maps using a new computational tool to map the glomerular layer of the olfactory bulb

Odor quality is thought to be encoded by the activation of partially overlapping subsets of glomeruli in the olfactory bulb (odor maps). Mouse genetic studies have demonstrated that olfactory sensory neurons (OSNs) expressing a particular olfactory receptor target their axons to a few individual glomeruli in the bulb. While the specific targeting of OSN axons provides a molecular underpinning for the odor maps, much remains to be understood about the relationship between the functional and molecular maps. In this article, we ask the question whether intensive training of mice in a go/no-go operant conditioning odor discrimination task affects odor maps measured by determining c-fos up-regulation in periglomerular cells. Data analysis is performed using a newly developed suite of computational tools designed to systematically map functional and molecular features of glomeruli in the adult mouse olfactory bulb. This suite provides the necessary tools to process high-resolution digital images, map labeled glomeruli, visualize odor maps, and facilitate statistical analysis of patterns of identified glomeruli in the olfactory bulb. The software generates odor maps (density plots) based on glomerular activity, density, or area. We find that training up-regulates the number of glomeruli that become c-fos positive after stimulation with ethyl acetate.