University of Chicago Seminar

****RESCHEDULED TO FEBRUARY 16th*****

Hey Chicago people, I will be giving a seminar next week to the University of Chicago Animal Behavior Group. If you're in the area and want to learn about litter size and life history in marmoset monkeys, please check it out!

Wednesday, February 16th at 12:00 pm
Room 122, Biopsychological Science Building
940 E. 57th Street

Bigger isn't always better: Effect of birth condition on reproductive outcomes in female marmoset monkeys

Life history theory predicts that early life conditions that reflect metabolic or environmental stress may accelerate life histories. Birth weight is traditionally the most common proxy measure of the quality of the intrauterine environment and it is linked to postnatal and adult outcomes in many species. However, birth weight alone does not reflect the entirety of these intrauterine processes. Litter size is another source of variation in the quality of the prenatal environment. In this talk, I report findings from a captive marmoset monkey colony suggesting that litter size at birth is an independent predictor of accelerated life history parameters as well as reduced fecundity. Triplets are born at significantly lower birth weights than twins and have higher perinatal mortality risks, but exhibit trends toward greater postnatal growth rates and higher early adult ages, especially among triplets born at the lowest weights. Further, although twins and triplets don’t differ in the total number of offspring they produce over their reproductive tenure, mothers who themselves were born into triplet litters produced over twice as many stillbirths as did twins. The mechanisms underlying this high proportion of stillbirths are unknown but could be related to developmental constraints on the viability of the ovarian follicle pool or size and function of the uterus, constraints that are separate from limits on overall somatic growth. These findings suggest that early life processes separate from birth weight have a significant impact on adult reproductive function with important implications for demographic composition and life history evolution.