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An Innovative Outdoor Primate Housing Unit

JOSEPH L. WAGNER PEGGY O'NEILL-WAGNER

Authors describe the University of Miami's innovative approach to housing captive nonhuman primates. They discuss and describe the caging materials and designs used to enhance life for the rhesus monkeys and the animal husbandry staff.

KEY WORD INDEX:: monkeys, animal welfare, animal husbandry, animal housing, cages

About the Author

Some research and zoological institutions are developing methods of captive housing for nonhuman primates in order to establish and maintain compliance with Federal animal welfare regulations. Since the behavior and overall health of nonhuman primates have been shown to vary relative to characteristics of their physical and social environment (O'Neill, 1989; O'Neill-Wagner, 1994; Boyce et al., 1994), it is essential to provide surroundings that serve all health aspects of the animals. Housing primates outdoors, particularly in a subtropical climate such as Florida, enriches them because it provides more diversity, thereby enhancing stimulation of all the senses. Primate behavior has been shown to change in positive ways following the introduction of apes, lemurs, and monkeys to outdoor settings (Clarke et al., 1982; Macedonia, 1987; Chamove, et al., 1989; O'Neill et al., 1991). But, placing the animals outdoors may lead to challenging animal care issues. For this reason, the outdoor enclosure space should be designed so it is manageable and maintainable, for the sake of the animals as well as the animal husbandry staff.

The University of Miami has housed rhesus monkeys outdoors in corncribs since 1980. These structures, originally designed for the agricultural industry to store dried field corn, were adapted many years ago to provide suitable outdoor housing for the monkeys. Later, however, it was learned that exposure of the animals to the galvanized coating on the steel structure rods sometimes resulted in a zinc toxicity and subsequent copper deficiency in newborns referred to as fading infant. Suckling infant monkeys exhibiting this abnormal white hair coat were characterized by a failure to thrive, severe anemia, and occasional death (Obeck, 1978).

The design and construction of a new and unique outdoor housing system for nonhuman primates began in 1989. Made entirely from aluminum, it eliminated the potential hazards of zinc. To enhance stability and anchoring, the original round caging design gave way to an octagonal shape, with a floor area of 105 square feet. Named the Miami Module , this 13 feet tall unit offers increased functional space for monkeys (figure 1) as well as ease of animal care and cleaning.

Figure 1. Figure 1: Interior design provides functional space.

For animal comfort and stimulation of species-typical behaviors each unit has the following components: -- adjustable aluminum resting platforms arranged at different heights,

-- one aluminum fixed platform (3.5 feet wide) extends the entire width of the module and is held by a reinforced rail support system which adds support to the walls beneath it,

-- one aluminum ladder extends from the floor to the permanent fixed perch,

-- two stainless steel removable feeders with locking hinged lids and spring loaded latches at the bottom which are slipped into panels,

-- three automatic watering lixits available at separate locations above the floor line. Staff benefits to the module include the following components: -- one personnel access door with a latch that opens out into a mobile personnel access cage measuring 7 feet long X 5.5 feet wide X 6.5 feet tall,

-- each personnel access cage is on casters and can be transported to and from the cage where hooks hold it in place,

-- three guillotine doors are designed to dock with a ten foot portable chute system allowing adjacent modules to be joined,

-- each chute has four removable panels (side-loaded, solid panel dividers) which can compartmentalize the chute, allowing free or restricted movement of the animals
(figure 2),

-- a squeeze mechanism is found within the chute.

Figure 2. Figure 2: Portable chute system joins two modules.

Enrichment devices that are not components of the module, but were later added for the monkeys in each module include: -- pickle barrels; large polypropylene barrels with both ends open, hung beneath the fixed perch which is strong enough to support two barrels with the weight of all animals using them (Lehman, et al., 1992). These shelter areas offer weather protected resting areas, increase usable space in the modules, and provide visual breaks and privacy (figure 3),

-- one or two milk crates (O'Neill, 1988),

-- one or two primahedrons (O'Neill, et al., 1990),

-- two to four plastic chains,

-- two to four swinging rings.

Figure 3. Figure 3: Plastic pickle barrels in each module provide weather protection,
rest areas, increased space, visual breaks, and privacy.

Some modifications have been made since the first modules were constructed in 1989. The original floor material, a plasticized tenderfoot flooring - expanded metal covered with rubberized plastic - was not suitable for rhesus monkeys. The plastic coating was chewed by the rhesus, thereby exposing the metal to weather.
The resulting rust was not easily cleaned. Replacing this with a suspended tubular aluminum flooring was finally successful but only when the elliptical aluminum tubing was mounted on top of supporting braces. Spacing of this tubular design was also modified to 1/2 inch so that the monkey biscuits could not easily fall through
(figure 4). The flattened surface provided by this design also facilitates cleaning.

Figure 4. Figure 4: Suspended tubular aluminum flooring keeps monkey
biscuits in the cage and is easily cleaned.

An inherent problem with the original corncrib structures was that conical-shaped roofs tended to pick up wind. High velocity winds and wind gusts could seriously damage the structures. The University of Wisconsin lost one corncrib due to a Tornado in 1975.

At first, Miami module roofs were modified by sandwiching Styrofoam sheets between aluminum sheets, providing a flat roof. This was securely fastened across the top of the module. These roofs were damaged during high winds too; the University of Miami lost sixteen module units due to Hurricane Andrew in 1992. A later design focused on a tear-away roof top, leaving the caging below intact, should the roof be subjected to high winds. The fiberglass sheeting first used was too fragile. The problem was solved when rigid aluminum rod ceilings were covered with six sheets of lexan (corrugated 3 feet X 12 feet plastic panels) and attached with 3 inch PVC supports. This roof will tear away from its support structure, significantly reducing wind resistance (figure 5). Since its implementation, this feature has proven very successful during severe weather and powerful wind gusts.

Figure 5. Figure 5: Come windy weather, the tear-away roof design
leaves the cage below intact.

An improved anchoring system is also being used. A series of four 3/8 stainless steel cables with turnbuckles are used to fasten each module to eye bolts imbedded in the cement slab. The same procedure can be used on gravel if eight cement pillars are installed.

ACKNOWLEDGEMENTS

Many thanks are extended to the following individuals for their efforts toward the completion of the Miami Module : Linda Taylor, Ph.D., Carol Emerson, D.V.M., Elysse Orchard, D.V.M., and Frances Doepel, D.V.M.

REFERENCES:

Boyce, T.W., O Neill-Wagner, P.L., Price, C.S., Haines, M., & Suomi, S.J. (1994). Stress reactivity and violent injuries in free-ranging rhesus monkeys (in preparation). Presentation to the Annual Meeting, Society for Pediatric Research, Seattle Washington, 5 May, 1994.
Chamove, A.S., & Rohrhuber, B. (1989). Moving callitrichid monkeys from cages to outside areas, Zoo Biology, 8, 151-163.
Clarke, A.S., Juno,C.J., & Maple, T.L.(1982). Behavioral effects of a change in the physical environment: A pilot study of captive chimpanzees. Zoo Biology, 1, 371-380.
Lehman, S.M. & Lessnau, R.G. (1992). Pickle barrels as enrichment objects for rhesus macaques. Laboratory Animal Science, 42, 392-397.
Macedonia, J.M. (1987). Effects of housing differences upon activity budgets in captive Sifakas (Propithecus verreauxi). Zoo Biology, 6, 55-67.
Obeck, D.K. (1978). Galvanized caging as a potential factor in the development of the fading infant or white monkey syndrome, Laboratory Animal Science 28:6, 698-704.
O'Neill, P.L. (1988). Developing effective social and environmental enrichment strategies for macaques in social groups. Lab Animal, 17, 23-24.
O Neill, P.L. (1989). Short-term and long-term benefits of environmental enrichment on laboratory raised rhesus monkeys (Macaca mulatta). American Association of Zoological Parks and Aquariums Regional Conference Proceedings, 616-625.
O Neill-Wagner, P.L. (1994). Expression of species-specific behavior in rhesus monkeys relative to features of their environment. Lab Animal, Nature Publishing, Inc. (In Press).
O'Neill, P.L., Novicky, P., & George, E. (1990). Preliminary evaluation of primahedron play structures for primates. Lab Animal, 19, 40-41.
O Neill, P.L., Suomi, S.J., & Novak, M. (1991). Normalizing lab-reared monkey behavior with exposure to outdoor naturalistic environments. Zoo Biology, 10, 237-245.

Joseph L. Wagner

D.V.M.
Division of Veterinary Resources
University of Miami
Miami, Florida

Dr. Wagner became Doctor of Veterinary Medicine at Ohio State University in 1967 and achieved Board Certification as
Diplomate, American College of Laboratory Animal Medicine in 1974. His professional career began at the University of North
Carolina, Chapel Hill. After five years of service there, he accepted the position
of Director for the Division of Laboratory Animal Resources at Duke University. From 1979 until the present, Dr. Wagner has been the Director for the Division of Veterinary Resources at the University of Miami,
Miami, Florida where he also serves as
Professor of Microbiology and Immunology. Dr. Wagner is an active participant in the National Institutes of Health AIDS Animal Model Program.

Peggy O Neill-Wagner

Research Psychologist
National Institutes of Health
Poolesville, Maryland

Peggy O'Neill-Wagner is a Research Psychologist for the National Institutes of Health. She has studied primate behavior since she graduated in Psychology from the Uni-
versity of Wisconsin in 1971. After studying Wildlife Management and Ecology at the Universities of Wisconsin and Minnesota, she was invited back to Wisconsin to continue her graduate training in Psychology with Dr. Harry Harlow. In Wisconsin, Peggy studied free-ranging primates for nine years.

In 1984, Peggy joined the research staff at the Laboratory of Comparative Ethology, National Institutes of Health. Since that time she has received numerous awards and acknowledgements for her accomplishments in primate behavior research, state-of-the-art husbandry practices, and innovative techniques for enriching the lives of primates in captivity. She has traveled extensively to share her findings with other professionals in many fields including veterinary medicine, animal care, child development, wildlife conservation, zoo animal management, facility and exhibit design, as well as federal and State animal welfare regulation and enforcement.

Joe and Peggy Wagner met during the aftermath of Hurricane Andrew. NIH sent Peggy and other federal professionals to assist Dr. Wagner as relief workers. Their marriage was one positive outcome of the natural disaster.

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