Wood as an enrichment device for primates (2009)

Gallucci, P., Cliett, M. L., Stewart, A.

Abstract

Our facility houses approximately 300 cynomolgus macaques. Providing stimulating environmental enrichment for them without unreasonably increasing staff time can be challenging. Our current enrichment program includes multiple toys, mirrors, forage trays, sound machines, music, videos, and a variety of fruits, vegetables, and snacks. We wanted to supplement our existing enrichment program without adding yet another food item to their already varied diet. Our goals were to engage our primates in a time-consuming activity that somewhat mimicked their natural habitat and to provide an enrichment activity that would reduce stereotypic behavior. We needed to accomplish this without placing an undue burden on our husbandry staff.We identified a vendor (Bio-Serv, Frenchtown, NJ) that supplies several types of wood enrichment products. They use only deciduous tree branch pieces freshly harvested from saplings grown in soil that is free from environmental contamination. They are offered in a variety of sizes and shapes with pre-drilled holes for hiding treats. These wood pieces can be sanitized or autoclaved as needed.We purchased a selection of 1.5 in. and 6 in. diameter red oak and maple wood pieces to use on a trial basis for one room of our primates. It quickly became evident that the wood was a tremendous success. Some primates immediately shredded the wood, while others chewed on it slowly and carried it around for hours. During the trial period we monitored the primates closely for injuries or intestinal problems associated with the wood, but we saw no adverse effects. The only downside we encountered was the occasional clogged drain due to an accumulation of shredded wood. To eliminate this problem, we are currently evaluating screen covers for the drains.We concluded that using wood for primate enrichment met or exceeded all of our goals. Allowing our primates to exhibit species-specific behavior by providing a little piece of their natural habitat was very rewarding for us. Distribution, cleaning, and drain maintenance was far less labor intensive than providing puzzle boards, fleece boards, challenger balls, and similar products, allowing interactive enrichment on a more regular basis. We are currently providing this enrichment several times a week for primates prone to stereotypic behaviors, particularly over-grooming. Our plan is to institute wood once weekly as part of our regular enrichment program for the remainder of our primate colony.