A demographic analysis of the Wisconsin Regional Primate Center rhesus colony, 1962-1982

A detailed demographic analysis was made of the Wisconsin Regional Primate Research Center rhesus colony from vital statistics recorded over a 20-year period. Techniques used were based on demographic and epidemiological methods developed for human populations, which provide the potential for making standardized measurements within captive primate colonies. A life table based on 1,086 deaths showed an abnormally high survivorship at the older ages, probably caused by a tendency to retain especially robust animals for breeding purposes. During the period of study, 2,194 animals were removed for sale or research. Removal rates were relatively uniform across ages. Age-specific fertility rates based on 1,616 births occurring during the second decade showed a relatively rapid increase in births from about age 2 through age 12, with peak fertility persisting until about age 20. Vital events showed significant seasonality, with a birth peak in April and May. Analysis of the stable age structure (excluding removal) showed an intrinsic growth rate of 6.3%. With removal rates added, the growth rate dropped to -0.3%. Although the use of these methods is probably warranted onlyby the level of detail found in captive colony records, analysis of captive colonies can provide information relevant to the demography of wild primates.