Mate reinforcement value and the pair bond in ring neck dove (Streptopelia risoria)

Abstract

During the breeding season, monogamous birds form partnerships characterized by preferential involvement in reproductive and parental behaviors with a mate. The breeding partnership is dependent on a ‘pair bond’, an adhesive force that promotes prolonged affiliation and behavioral cooperation between two birds. Here we propose that the adhesive force of the pair bond is at least partially the result of the acquired reinforcement value of the mate. If the mate becomes a reinforcer during courtship then through classical conditioning principles the mate will reinforce affiliative behavior evident in pair-bonded birds. The present experiments were designed to determine whether the pair-bonded mate of ring neck dove (Streptopelia risoria) acquire reinforcement value during the reproductive cycle. Mate reinforcement value was assessed using a conditioned place preference paradigm in which the mate was paired with a visually distinct context and a second distinct context was paired with social isolation (Experiment 1) or an unfamiliar bird of the opposite sex (Experiment 2). Both males and females preferred the context that had been paired with the mate to the context paired with social isolation or an unfamiliar dove. The results suggest that pair-bonded mates are stronger reinforcers than unfamiliar birds. Experiment 3 found that the preference for the mate context over the unfamiliar dove context was stronger during incubation than during courtship. The possible involvement of a classical conditioning process in the maintenance of the pair bond is discussed.