Development of the Morgan Island rhesus monkey colony

During the summer of 1979, the rhesus monkey breeding colony of the La Parguera facility of the Caribbean Primate Research Center was shipped to Morgan Island, South Carolina. During six shipments in 1979, and three more in 1980, over 1400 animals were translocated. Mortality from shipping, primarily in infants, was approximately 0.65%. Although the monkeys were not shipped in intact social groups, they restablished their groups shortly after subunits were released onto Morgan Island (MI). Since 1979 the colony has grown almost four-fold and now numbers almost 4000 animals. There has always been a strong female bias in the colony and today females comprise 75% of the total population. That portion of the colony comprising the aged animals, especially females, has grown steadily and today is 13% of the total. Except for the first year, when the colony was translocated during its mating season, reproduction at MI has been good, with a pooled average pregnancy rate of almost 80% and live birth rate of 71%. Juvenile females have also reproduced well, averaging 76% pregnancy and 70% live birth rates. This experience demonstrates that with proper planning and execution, a large, free-ranging colony can be moved long distances with minimal stress, trauma, mortality or disruption of social structure and reproduction.