Effects of trapping on the vervet (Cercopithecus aethiops sabaeus) population in Barbados

The effects of a 7-year trapping program on a population of vervets, Cercopithecus aethiops sabaeus, in Barbados is described. The pretrapping population was estimated at between 6,000 and 12,000 monkeys. The number trapped annually has increased from less than 200 in 1980 to almost 1,000 in 1986. Despite this, annual catch per trapping effort indicates that population abundance has remained relatively constant. However, the proportion of juveniles to adults in the population has increased markedly, largely because of an increase in the proportion of juvenile females. The data, therefore, suggest that the number of adults in the feral population has been decreasing, while that of juveniles has been increasing. The observation that adults are more vulnerable to trapping than juveniles and the possibility that juvenile survivorship has increased since trapping began may explain these trends. The change in age structure of the population toward juveniles is one explanation for the claimed increase in crop damage in Barbados at constant population size.