“Training” is now mainstream in many zoos and aquariums. Specifically, positive reinforcement training is being utilized to achieve a wide range of medical, husbandry, and public presentation behaviors in a multitude of zoological species.
Positive reinforcement training fits within a larger field of behavioral analysis and the techniques are applicable within and outside of the zoological field.3,6,9,10,15 Behavioral analysis is the study of behavior change; how individuals learn behavior (i.e., operant behavior or conditioning).2,5 Applied behavioral analysis is the utilization of this science “in the real world.” The laws and rules that govern learning in individuals provide a robust method for examining behavior, productively evaluating and reducing problem behavior, and teaching (training) specific behavior.2,6,9,15 They are conserved across species and thus applicable to all animals.
Behavior and why behavior develops or changes can be examined through a variety of sciences (e.g., neuroendocrine, genetic, physiology, etc.). As veterinarians, we are trained to consider medical causes for behavior or behavior change. For example, increased aggression (e.g., biting when touched) may be due to pain or a brain tumor. In the zoological field, we often consider natural history or evolutionary causes for behavior or behavior change. For example, biting may be from territorial defense during breeding season. In addition to these more familiar methods of behavior evaluation, behavioral analysis is critical for understanding how behavior develops, and is maintained in an individual animal.5 For example, biting developed because it was reinforced in the past; the animal has learned to do the behavior. These approaches are not mutually exclusive and integration is often integral to successful training and problem behavior intervention.
An excellent review of applied behavioral analysis for veterinarians exists.5 The review examples are from parrots, but as noted above the principles are conserved across species. Certain highlights are presented below.
Behavior is a function of its consequence (The Law of Effect). A consequence is a stimulus, event, or condition that influences the strength of future behavior.5 Reinforcers are consequences that maintain or increase a behavior; punishers are those that decrease behavior. The consequence is defined by what it does to behavior, not what it is.5 Consequences can also be categorized based on input; positive if added to the environment and negative if removed/escaped/avoided. Positive and negative are mathematic concepts; there is no connotation of “good/bad.” Thus, there are four consequence options (also called quadrants); positive reinforcement (“reward”), negative reinforcement (“escape”), positive punishment (“discipline/correction”), and negative punishment (“penalty/fine”) as displayed in Table 1. It is the learner who determines if something is reinforcement or punishment.5 If you yell “stop it” when your dog barks and barking increases in frequency, intensity, duration, etc. then yelling is reinforcement to the dog, no matter what you want it to be!
Table 1. Summary of the four consequence optionsa
Reinforcement (increase behavior)
Punishment (decrease behavior)
Positive Reinforcement (R+)
Addition is desired
Commonly called: Reward
Positive Punishment (P+)
Addition is aversive
Commonly called: Discipline/correction
Negative Reinforcement (R-)
Aversive is in antecedent
Commonly called: Escape
Negative Punishment (P-)
Removal is aversive
Commonly called: Fine/penalty
aModified from: Freidman SG, Edling TM, Cheney CD. Concepts in behavior: Section I. In: Harrison GJ, Lightfoot TL, eds. Clinical Avian Medicine Volume I. Palm Beach, FL: Spix Publishing Inc.; 2006:46–59.
Whether a consequence is reinforcement or punishment can only be fully evaluated by observing what actually happens to behavior in the future. Based on understanding an individual animal or species in general, it is possible to predict the likely impact of consequences on behavior. This predication is part of the basis for implementing purposeful training programs and developing problem behavior interventions. However, the actual impact on behavior must be evaluated to test if the prediction is correct.5
Behavior is never evaluated alone but is always considered within the context of the environment immediately surrounding the behavior and functionally related to it. Thus, the smallest unit to evaluate behavior is the behavior (B) with the environmental brackets of the antecedent immediately before the behavior (A) and the consequence (C) immediately after the behavior (A-B-C).5 The observable behavior of interest is defined first, using clear, concise language to describe the relevant behavior. Then the consequence and antecedent are identified and described. The ability to list and understand the functional relationship between a behavior and the environment around it is extremely important when trying to reduce problem behavior.5 The functional analysis (A-B-C) becomes, in effect, a hypothesis to identify what, exactly, the problem behavior is and what consequences may be maintaining that behavior as well as the environmental cues that elicit the behavior. This functional relationship between A-B-C is also the fundamental relationship that is developed when specific behaviors are purposefully trained.
This process of receiving feedback from the environment and feedback modifying future behavior (i.e., learning) is completely natural and happens constantly “in the wild” as well as “in captivity.”2 While we may use it to purposefully train behavior, it is functioning at all times and not just in training sessions. Every interaction humans have with the animals in their care creates a “learning” opportunity. In addition, the animal’s interactions with other animals and the overall environment will also be providing constant feedback as to the effectiveness of behavior.
There are predictable negative side effects to living in environments that provide higher amounts of negative reinforcement, positive punishment, and/or negative punishment than positive reinforcement.5 These include apathy/reduced activity, aggression, escape/avoidance, and over-generalized aversion to environment.2,5 There is increasing focus in all areas of captive animal management on purposeful training using positive reinforcement and also establishing environments that are filled with opportunities for animals to “naturally” obtain positive reinforcement (i.e., enrichment). Enriched environments that provide opportunities for choice, control, and positive reinforcement have been linked to improved behavioral and physical health in a variety of studies.1,4,7,8,11-14,16
Increased understanding of the scientific principles that underline how individuals learn behavior can allow veterinarians to more productively help prevent or manage behavior problems in captive animals and assist husbandry staff in training desired medical behaviors.
The author would like to thank Dr. Susan G. Friedman at Utah State University for her support and training and dedication to improving the lives of captive animals as well as Ms. Sue Hunter at National Aquarium Baltimore for her provision of regular “on the job” training.
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