HORMONES

In the quest to understand why some male monkeys mate in a monogamous relationship, presumably foregoing other reproductive opportunities and often investing heavily in the care of offspring they are not certain to have sired, we began to collect data to describe the possible hormonal mechanisms regulating sexual monogamy in owl, titi and saki monkeys.

Using fecal samples, we can also evaluate male and female reproductive hormone profiles to test patterns in hormone and reproductive profiles. To what extent are males precluded from polygyny because of female reproductive synchrony? Are there differences in testosterone profiles that may be related to parental behavior? Do males make possible trade-off between parental care and territoriality as reflected in testosterone levels? Do males and females subadults reach sexual maturity while in their natal groups?

In collaboration with Dr. Valeggia’s Reproductive Biology Lab at Yale University, we have analyzed the endocrinology data of sexual monogamy, biparental care, and dispersal patterns in owl monkeys.