The role of the endocrine system in baboon maternal behavior.
BACKGROUND
Human mothers display a wide range of parenting skills, and although we have gathered a large body of evidence on a variety of factors affecting maternal behavior, we still know relatively little about the physiologic correlates of variation in parental behavior in primates.


METHODS
Excreted gonadal and adrenal steroids were measured across parturition in a large sample (n = 89) of group-living female baboons. Maternal behavior data were collected during the first 2 months of infants' life.


RESULTS
We found that changes in the excreted sex steroid hormones and cortisol were associated with baboon mothers' infant-directed behaviors. Mothers who displayed more stress-related behaviors, who were also prone to maintain less contact with their infants, had higher postpartum cortisol levels, higher prepartum pregnanediol-3-glucoronide (PdG) levels, and lower postpartum PdG levels. Mothers with higher prepartum cortisol levels showed higher levels of infant-directed affiliative behaviors.


CONCLUSIONS
These results point toward the importance of the whole endocrine system as a functional unit in terms of enhancing maternal care in primates. The dramatic physiologic changes occurring across parturition may act, in coordination with the cognitive-experiential system, to help the mother cope with the additional challenges imposed by the newborn.
Bardi
Massimo
M
Department of Comparative Medicine, Southwest Foundation for Biomedical Research, San Antonio, Texas 78245-0549, USA.
French
Jeffrey A
JA
Ramirez
Stephanie M
SM
Brent
Linda
L
D000818:Animals; D001143:Arousal / Q000502:physiology; D004703:Endocrine System / Q000502:physiology*; D005260:Female; D012739:Gonadal Steroid Hormones / Q000652:urine; D006854:Hydrocortisone / Q000652:urine; D008425:Maternal Behavior / Q000502:physiology*; D009769:Object Attachment; D010215:Papio / Q000502:physiology*; D011247:Pregnancy; D011276:Pregnanediol / Q000031:analogs & derivatives* / Q000652:urine; D012016:Reference Values
D012739:Gonadal Steroid Hormones; C022270:pregnanediol-3 alpha-glucuronide; D011276:Pregnanediol; D006854:Hydrocortisone