Using Negative Reinforcement to Promote Non-Agonistic Behavior in a Green Iguana (Iguana iguana)

Green iguanas (Iguana iguana) are a large, long-lived reptile well-equipped to defend themselves against predators and territorial conspecifics. These increasingly common household pets often respond to human caretakers with anti-predator behaviors including hissing and tail whipping. Current green iguana literature recommends long-term socialization training without any well-defined protocols. Animal behaviorists recommend positive reinforcement training whenever possible; however, negative reinforcement may be a suitable alternative when working with frightened or aggressive animals. Removal of aversive human presence contingent on the subject animal’s behavior has been shown to promote calm and friendly behaviors in domestic cats (Felis catus), domestic dogs (Canus lupus familiaris), and petting zoo sheep (Ovis aries). Negative reinforcement research has primarily focused on domestic mammals, but high-level learning capabilities have been demonstrated in a variety of reptile species. Thus, the present study aimed to apply negative reinforcement training to promote non-agonistic behaviors in a captive green iguana. Following 12 days of negative reinforcement training, an increase in non-agonistic behaviors were observed with a decrease in the overall number of agonistic displays and types of agonistic behavior presented. This study indicates that the previously described negative reinforcement protocols for domestic mammals also promote non-agonistic behaviors in a captive pet green iguana utilizing a naturally occurring and unavoidable stimulus to promote behavior change in a least intrusive manner.