consensus suggests that in addition to physical health the following criteria are important in assessing psychological well-being:

  • The animal's ability to cope effectively with day-to-day changes in its social and physical environment (with reference to meeting its own needs).
  • The animal's ability to engage in beneficial species-typical activities.
  • The absence of maladaptive or pathological behavior that results in self-injury or other undesirable consequences (see Bayne 1996 for a discussion of the normal and abnormal behaviors).
  • The presence of a balanced temperament (appropriate balance of aggression and passivity) and absence of chronic signs of distress as indexed by the presence of affiliative verses distress vocalizations, facial expressions, postures, and physiological responses (e.g., labored breathing, excessive cardiac response, and abnormal hormonal concentrations).

None of those criteria can stand alone as the defining measure of psychological well-being in captive primates. However, when used together, they might provide a detailed picture of a primate's psychological health.

In assessing general well-being, physical health is probably the easiest to assess on the basis of established veterinary procedures for captive nonhuman primates (Bennett and others 1995; Keeling and Wolf 1975). Routine health examinations given at specified intervals are usually supplemented with daily inspections of an animal to monitor for such variables as hair condition, alertness, gait, appetite, body weight, and injury. The inspections can be used to identify potential problems in both psychological and physical well-being. Good physical health, however, is not synonymous with good psychological health. Psychologically disturbed animals might appear to be in good physical condition, and evidence of poor physical condition does not preclude psychological well-being. For example, elderly monkeys can show signs of clinical disease, such as arthritis, but maintain social ties, breed successfully, and appear alert and responsive to environmental stimuli.

Two general principles are important in assessing behavioral indicators of psychological well-being. First, there should be behavioral diversity; animals should exhibit a broad range of species-typical patterns of behavior. That does not mean that every species-typical behavior described for a given species in nature need be exhibited by captive members of that species; this is neither possible in all cases (e.g., providing space equivalent to an animal's daily movements in nature) nor necessarily desirable (e.g., recreating intertroop conflicts, predator attacks, weather extremes, droughts, and environmental hardships). But captive primates should be provided with suitable opportunities to express a variety of species-typical behavior.

The second principle is that some kinds of species-typical behavior might be better indicators of psychological well-being than others. For example, repro-



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