We propose to establish a dedicated breeding colony of chimpanzees (Pan troglodytes) that will produce between 10 and 14 healthy and behaviorally normal offspring per year. These offspring will be used to establish a stable, self-sustaining breeding population of chimpanzees that will guarantee the future availability of these animals for biomedical and behavioral research and testing. We propose to conduct the breeding program utilizing an existing stable social group of chimpanzees, pair matings using known breeder animals and artificial insemination of females that do not breed spontaneously. Infants will be managed in such a way as to maximize social experience, including extensive mother-rearing where possible, peer group-rearing when nursery care is required and fostering of nursery-reared infants onto competent mothers. We also propose to conduct research in areas that will promote improved reproductive success and efficiency and improved behavioral outcome. This research will include investigation of early detection of labor using telemetry to allow early and effective assistance when required and thus improve neonatal survival; investigation of hormonal manipulation to shorten interbirth intervals without the need to separate infants from their mothers; methods of gamete preservation to improve artificial breeding techniques and permit maintenance of genetic lines and to promote genetic diversity; and investigation of early rearing techniques in order to develop techniques that are conducive to subsequent successful reproduction and to identify behaviors that are predictive of future reproductive performance.