and monitoring it should have knowledge of and experience with nonhuman primate behavior. They should attempt to predict and prevent harm to the animals caused by social partners, or even toys, on the basis of their knowledge of their animals. They should be alert to subtle changes in behavior, noting improvements due to enrichment or declines due to illness or other stressors. Periodic training of staff to acquaint them with advances in the field is essential.
Personnel should be aware of safety precautions needed to prevent physical injuries and disease transmission between themselves and the animals. Some enrichment techniques and devices that necessitate daily setup can place a caregiver at increased risk and are inappropriate with many animals. Good judgment in these cases requires individual knowledge of the animals, and caregivers should be encouraged to interact in positive and nonthreatening ways with their animals. Personnel practices that result in frequent exposure of primates to unfamiliar caregivers can also be stressful to animals and should be avoided.
Nonhuman primates and their caregivers must be protected from exposure to hazardous agents. Appropriate protective clothing is required to prevent transmission of disease to humans and to animals, particularly when infectious agents are involved (Bennett and others 1995; CDC-NIH 1993; NRC 1997a). Whereas protective clothing does not preclude forming individual relationships between animals and personnel, the use of a standard uniform, with minimal individual variation, hinders individual identification. It is sometimes advantageous to wear attire peculiar to individual caregivers or procedures (e.g., cleaning and feeding versus handling), rather than a standard uniform. It might convey useful cues to the animals and avoid undue alarm over a potential capture every time a person enters the room. Where possible, staff should avoid barriers that hinder the development of individual relationships between nonhuman primates and the people that care for them. The committee believes that the use of masks, face shields, gloves, and special uniforms should be based on specific needs to protect against identified hazards (NRC 1997a). The intense sociality of many primates is often expressed in forming social relationships with humans (Bayne and others 1993a; Hummer and others 1969; Wolfle 1985); these relationships not only might enhance the psychological well-being of the animals but also will facilitate many routine and even unusual procedures (see "Restraint and Training" earlier in this chapter). A familiar caregiver can often encourage an escaped animal to return to its usual housing or induce an animal to accept medicated food.
Interactions between humans and nonhuman primates can be made less stressful by adherence to routine schedules and procedures, familiarity with handlers and researchers through positive interactions outside the handling context, and the use of training procedures to elicit cooperation and thus minimize force or restraint (Chambers and others 1992; Phillippi-Falkenstein and Clarke 1992; Reinhardt 1990a, 1991b, 1992a, b; Reinhardt and Cowley 1992; Vertein and