Changes in the routine of the howler monkeys Alouatta guariba clamitans Cabrera, 1940 and of Alouatta caraya Humboldt, 1812 in zoo managed through environmental enrichment techniques.

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Abstract

Currently, many zoos have larger environments which provide adequate physiological care and fulfill behavioral needs of their animals than captive animal enclosures commonly used in the past. However, even with such improvements these environments can still be stressful to animals as they are relatively less complex as compared to wild and contain few stimuli. This may lead to atypical behaviors, apathy and gradual loss of attention and the ability to search for new stimuli. Among the aims of environmental enrichment (EA) techniques is the increase the behavioral repertoire of animals kept in zoos by encouraging the natural behavior of species. The objectives of this study were to evaluate the behavior of captive Alouatta guariba clamitans and Alouatta caraya individuals by observing the behavioral changes resulting from environmental enrichment and, if among the offered elements, some are more attractive to animals. For this, we compared the behavior of two groups of howler monkeys in zoo during periods with and without environmental enrichment, considering six different environmental enrichment devices. Howler monkeys responded well to stimuli by interacting with all devices presented. However, there were not any significant changes in the activity pattern for environmental enrichment for any group. Yet, environmental foraging increased after the use of the enrichment technique, indicating that the animals can be interested in different types of food. In addition, we observed a greater curiosity for devices that give food as reward. Thus, we observed that the environmental enrichment offered to individuals was able to promote positive changes in the routine and behavior of the animals, so it may be indicative of the improvement in animal welfare conditions. Besides, the devices presented may serve as an example of EA techniques to be applied in other captive situations, including rehabilitation of animal specimens that are able to return to nature.