The development of an operant conditioning training program for new world primates at the Bronx Zoo

This article describes the development of an operant conditioning training program for 17 species of New World primates at the Bronx Zoo. To apply less invasive techniques to husbandry protocols, the study introduced behaviors-hand feeding, syringe feeding, targeting, scale and crate training, and transponder reading-for formal training to 86 callitrichids and small-bodied cebids housed in 26 social groups. Individual responses to training varied greatly, but general patterns were noted among species. With the exception of lion tamarins, tamarins responded more rapidly than marmosets, Bolivian gray titi monkeys, and pale-headed saki monkeys in approaching trainers and learning behaviors. Marmosets, in comparison to most tamarins, had longer attention spans. This meant that fewer, lengthier sessions were productive whereas shorter, more frequent sessions were most successful for tamarins. Among the cebids, pale-headed saki monkeys needed relatively few sessions to perform basic and advanced behaviors whereas Bolivian gray titi monkeys were less responsive and progressed at a deliberate pace. Marked changes in the animals' behavior during daily husbandry procedures, their voluntary participation in training activities, and the disappearance of aggressive threats toward care staff indicated that training reduced stress and improved the welfare of the animals. During daily training displays, zoo visitors experienced interactive animals while learning the importance of low-stress animal husbandry.