Pigeons' choosing to go to work: Using reinforcement-based methods to balance animal welfare with research needs

We arranged conditions of social enrichment for a group of six pigeons as part of a larger program of research concerned with an animal model of gambling. When not in their experimental sessions, the pigeons lived together in a free-flying aviary, interacting with each other and with a physical environment that included perches, nesting materials, and nesting boxes. This enabled a range of species-typical social behavior including courtship, mating, and reproductive behavior. To minimize human involvement and the potential stress of daily captures, we devised procedures whereby the pigeons could choose to exit each day by flying one-by-one on cue into a box attached to the porthole door of the aviary from which they were transported to the test apparatus for their daily experimental sessions. By the end of this training, all pigeons were consistently entering the box independently in the presence of their own distinctive cues for transport to the session, and this continued for a maintenance phase during which each pigeon chose to participate in 120 daily sessions. The findings show the power of using reinforcement-based methods to solve practical problems in animal enrichment and welfare, balancing the welfare needs of the animals with the needs of the research.