Contributions to Science

Some of the pioneering contributions of Cayo Santiago:

Cayo Santiago monkeys have been used:

  • To discover the Rh factor.
  • To conduct malaria vaccine work during World War II.
  • For the development of the Hulka chip used in tubal ligation for reproductive control. 
  • For the first application of blood proteins to study biological divergence. 
  • For tetanus studies, which achieved the first known eradication of a population-wide chronic disease prior to the elimination of smallpox in humans.

Behavioral studies on Cayo Santiago have served as the foundation for central theories of social behavior in primates.

  • Some of the first systematic observations of primates which provided the foundation of our knowledge of behavior for primatology. 
  • The first longitudinal work which provided the basis for our understanding of primate dominance relationships. 
  • The first studies to help elucidate what factors determine dominance and how a troop is formed. 
  • The first studies to outline the importance of kinship in social structure. 
  • The first studies to show that monkeys have complex social relationships based around female relationships. 
  • Cayo Santiago rhesus macaques have consistently served as a human model for mother-infant relationships. These studies were the first to put primate development into a naturalistic context. The research conducted has examined cross-generational styles in maternal behavior as well as the interplay between social structure and mother-infant development. 
  • Behavioral differences related to dominance rank are linked to reproductive value of female rhesus macaques, according to an accurate life table. 
  • Among the first to show that female behavior affects male mating success and that it can counteract the effects of male-male dominance relationships. 
  • Primates recognize both maternal and paternal kin, and that they have preferential interactions with maternal and paternal kin over unrelated individuals. 
  • Data showing lifespan, not onset of reproduction, is the best predictor of lifetime reproductive success. 
  • The first data in free-ranging primates showing that changes in color are related to changes in behavior over time.