Prior to 2002 the Phoenix Zoo had identified the existing otter exhibit as deficient, both in terms of husbandry standards and the quality of public experience. Based upon visitor feedback, it was determined that this area of the zoo needed a reliable and more intense animal experience. The management was looking for a new type of exhibit that would give our guests a different perspective on animals. The availability of an appropriate and preferably cohesive group of monkeys was suggested and researched before the final commitment was made to the improvement.

We contacted Dr. Ken Gold about his experience as curator at the Apenheul Zoo in the Netherlands, and he was brought in to consult on the feasibility of a walk-through primate exhibit. Based on his advice, the zoo decided to build an exhibit — to be named Monkey Village — housing squirrel monkeys and saki monkeys together. The zoo already had the saki monkeys in its collection, and while the exhibit was under construction the management began searching for a group of squirrel monkeys. This group would preferably have more females than males, a common proportion both in the wild and in captivity.

Because the New World Primate TAG does not collaboratively manage common squirrel monkeys, they are not often bred in the zoo environment. Since there were no groups of captive squirrel monkeys that would be available within the necessary timeframe, we chose to obtain wild-caught monkeys. Wild-caught monkeys would be less used to people and more likely to maintain a larger flight distance from our guests, an important factor for liability issues. Working with the Bucksire Corporation, the Phoenix Zoo located and acquired 2.10 squirrel monkeys from Guyana. They arrived in pairs on April 29, 2003 from Bucksire Corporation's facility in Pennsylvania, and were immediately placed under quarantine in the Phoenix Zoo's Animal Care Center (ACC). In the ACC the animals were housed the same way they arrived, in pairs. All animals were tattooed on their inner left thigh and were shaved for identification.

After the 30-day quarantine, the squirrel monkeys were transferred into the Upper Education cages (an off-exhibit area, not open to visitors) for temporary housing. This consisted of six cages which permitted visual and tactile contact, but which did not allow the animals to have direct access to each other. This was the perfect setting to maintain the animals in pairs until the introductions could begin. After consulting several times with Leo Hulsker, Primate Supervisor at the Apenheul Zoo, and with Dr. Lawrence Williams, Assistant Professor at the Primate Research Laboratory at the University of South Alabama, we decided that since none of these primates had seen the new exhibit before, did not know each other well and had not have a chance to form subgroups yet, the best course would be to introduce all the animals together at the same time.

Since the animals were wild-caught, it was necessary to establish a feeding routine quickly, while they would be accustomed to seeing people but still not overly friendly toward them. While the animals were housed in the Upper Education cages, we began a new behavioral management program, which focused on teaching the animals to recognize feeding time through classical conditioning. Keepers wore orange-colored jackets while provisioning the monkeys, and always approached from the front of the section, to allow the animals to see the orange jackets clearly.

Figure 1.

All squirrel monkeys were uniquely shaved and tattooed for purposes of identification. Photo by Josh Crabtree.

At this point we were faced with a dilemma: the monkeys needed to be moved out from the small cages into a more natural exhibit, but Monkey Village was still under construction. The keepers started renovating another exhibit, this one open to the public, where the squirrel monkeys could be held temporarily until Monkey Village could be built. The keepers put an enormous effort into remodeling the exhibit: they changed all the branches, logs and ropes, painted all the walls with murals, provided extra hiding places and escape routes and redesigned the night house. By the end of June 2003 everything was ready for the introduction.

Figure 2.

Primary trainer Tracy Fleshman, wearing an orangecolored vest during feeding conditioning. Photo by Hilda Tresz.

The introduction took place on July 1, 2003 at 7:00 am in the temporary Squirrel Monkey Exhibit on the Discovery Trail. We decided that the best approach would be to leave the animals alone to work out their differences and to establish a social hierarchy; we would not intervene unless a severe injury occurred. An observation program was developed to document the introduction; due to a shortage of volunteers, we scheduled a combination of instructors, keepers, interns and volunteers to make observations for at least two weeks, including documentation on video.

Figure 3.

Common squirrel monkey exhibit on the Discovery Trail. Photo by Hilda Tresz.

The introduction was a complete success. The monkeys were released through their night house area to the exhibit. The animals spent their time cautiously looking around, testing the mesh and branches and foraging from their feed pans. Mating behaviors were observed and mostly were initiated by the dominant male. At first the two males spent a considerable amount of time huddling together, but by the second day they were seen joining some of the females. Aggressive chasing and grabbing was minimal among both sexes.

On the second day we released our male ocelot back into his own exhibit, directly across from the squirrel monkeys — he had been confined out of sight during their introduction — and the squirrel monkeys came together in a single group when he appeared. Our hot weather also aided us. On most mornings, the temperature rose above 90°F after 8:30 am, slowing all activities down; at those temperatures, the squirrel monkeys spent most of their time drinking and huddling in the trees, either by themselves or in groups of up to six individuals. All the animals acclimated very fast to their new environment and started to form bonds within a couple of days.

After the animals settled down, a second training program started. For medical and husbandry reasons the animals had to be taught to enter the night house every day. Wooden branches were provided to connect the night house entrance with the exhibit for easy access, and food was placed on it to lure the animals inside. They received novel food items only inside the night house, to encourage them to enter and explore. Keepers routinely entered onto exhibit, rang a bell and distributed food items as a reward; they gradually reduced the distance between the animals and the night house, and eventually the squirrel monkeys were only fed within.

In October the monkeys received their physical exams and were transferred into the Monkey Village holding area. We repeated the same night-house training program before they were introduced to the visitors. Monkey Village opened to the public on the weekend of November 13–14, 2004, and has been one of the zoo's most popular exhibits ever since.