Ultrasonographic Measurement of Fetal Growth in a Bonobo (Pan paniscus)

Starting about 4 mo before parturition, repeated ultrasonographic examinations were performed on a pregnant 27-yr-old bonobo (Pan paniscus). The bonobo was operant conditioned to allow all examinations to be performed while awake and unrestrained. To assess fetal growth and health, attempts were made to obtain biparietal diameter, head circumference, abdominal circumference, and femur length measurements at each examination. Once parturition had occurred, these measurements were plotted against time to produce fetal growth curves for the last 4 mo of bonobo gestation.