Dr. Bushmitz Mark Moshe, Veterinary Director of the B Virus-Free Cynomolgus Monkey Breeding Farm in Israel, Shares his Experience Minimizing Aggression in Group-House Macaques.
Monkeys are arboreal animals who are biologically adapted to spend most of their time high above the ground in trees—where they can keep distance from each other as needed. When they meet a predator on the ground, they inevitably climb the nearest tree, since sitting on a high branch gives monkeys a feeling of relative security.
We have kept breeding troops of cynomolgus monkeys for 17 years in large outdoor enclosures that address their biological and behavioral needs so well that they do not show any behavioral disorders. The animals are housed in large, two-story pens divided horizontally by a wooden floor with numerous openings that allow low-ranking animals to quickly escape and hide from potentially aggressive high-ranking group members.
The pens include many wooden shelves, ladders, climbing structures, swings and branches at different heights, making full use of the vertical dimension of their enclosure. If they want or have to, the monkeys can get away from each other instantaneously by leaping to another shelf or branch at a different height. Our monkeys spend almost all their time on these elevated structures, where they probably feel safe and secure. They come down to the ground to pick up or search for food, but they prefer to rest in the arboreal dimension of their living quarters.
There are also many big blinds made of colored plastic and suspended plastic barrels, behind and into which individual animals can escape to break visual contact with a dominant animal who threatens them. This is one way our monkeys avoid aggressive conflicts—out of sight, out of trouble!
In the wild, monkeys spend a major part of the day searching, retrieving and processing seeds, roots, fruits and insects. We entice our animals to forage by distributing sunflower seeds, dates and other small food items into sawdust or hay. The animals seem to be fascinated, searching with full concentration for food, then finally retrieving and eating it. While they are engrossed in foraging, our monkeys have no time to chase each other, so this kind of feeding enrichment helps to promote the social compatibility of the group.
The number one hit for our cynos is the swimming pool. They do not get bored jumping into the water, diving under with wide-open eyes to retrieve "goodies" such as raisins and corn from the bottom of the pool, or fishing for floating food items such as pomegranate. Sometimes they merely sit at the edge and play with the water.
Our monkeys give the impression of being content and perhaps even happy, and our experience shows that proper living quarters can help them adjust to confinement harmoniously.