Individualized Target Training Facilitated Transfer of Group Housed Capuchin Monkeys (Sapajus apella) to Test Cubicles and Discrimination of Targets on Computer Touch Screens

Abstract

Simple Summary Coercion and non-voluntary procedures can cause fear, anxiety and maladaptive behaviors for captive animals, which makes animal husbandry and care more difficult and reduces animal welfare overall. Positive reinforcement training (i.e., using rewards for desired behaviors rather than punishment for undesirable behaviors) is shown to be beneficial in reducing animals’ fear responses and in encouraging voluntary cooperation across a wide range of species. This paper outlines two experiments in positive reinforcement training to understand the importance of individualized targets in facilitating the voluntary transfer of captive capuchin monkeys (Sapajus apella) from their group enclosure to individual test cubicles. Experiment 1, which assigned different colored and geometric targets to each animal, rewarded animals for touching and following their assigned target into their test cubicle. The animals rapidly acquired the ability to identify their target, ultimately allowing them to cooperate by moving from one space to another voluntarily. Experiment 2 rewarded animals for spontaneously identifying their assigned target among other animals’ targets and novel targets. The animals chose their target more often than predicted by chance, although they did make some errors. Abstract Animals in captivity often experience fear, anxiety and aggression during non-voluntary procedures, leading to adverse behaviors and ineffective outcomes for both animals and caretakers. Negative reinforcement and punishment, often due to ignorance regarding animal learning, can hurt animal welfare. However, voluntary participation through positive reinforcement training (PRT) can decrease stress related to these procedures and increase desired behaviors. Our goal was to demonstrate the positive effects of “target training” on animal welfare by training 10 captive capuchin monkeys (Sapajus apella) in two experiments designed to facilitate movement from a group home enclosure to a test cubicle. In Experiment 1, each monkey was assigned an individualized target (a unique shape/color combination). In daily training sessions, the animal was rewarded with a click-sounding stimulus and a food reinforcer for (a) touching the target, (b) following the respective target into a test cubicle, and (c) touching progressively smaller targets until progressing to digitized images on a computer touch screen. All 10 animals learned to approach and touch their individual physical target in one or two sessions and were able to successfully transition this behavior to an image of their target on a touch screen, although they made more errors with the touch screen. In Experiment 2, the animals were presented with other animals’ targets and novel targets. The seven animals in this experiment all touched their target at higher-than-chance rates in Trial 1 without explicit discrimination training, but only five reached the learning criteria for the task (>83% correct for three consecutive testing days. These results demonstrate that target training can make voluntary movement from group housing to test cubicles easier and benefit future animal care and procedures.