Abstract # 43:

Scheduled for Thursday, August 17, 2006 04:15 PM-04:30 PM: Session 5 (Regency East #2) Oral Presentation

Failure rates for first pregnancy in captive adolescent female baboons (Papio hamadryas anubis)

T. M. Mueller
University of New Mexico, Department of Anthropology, Albuquerque, NM 87131, USA
     This present study aims to measure failure rates for the first pregnancy in a captive population, specifically analyzing miscarriage rates coupled with infant loss during the first two months of life. Data on social rank, resource acquisition, growth patterns, and reproductive state were collected on 61 adolescent female baboons (Papio hamadryas anubis) housed as part of a semi free-ranging breeding population at the Southwest Foundation for Biomedical Research and Southwest National Primate Center in San Antonio, Texas. These data indicate that the overall likelihood of miscarriage associated with first pregnancy approaches 60%, with the risk of miscarriage most strongly associated with the age at first pregnancy (p = 0.01) and the age at which crown-rump growth slows (p = 0.038). Females that are older adolescents at the time of their first pregnancy are more likely to miscarry than younger adolescent females. This may reflect a rank related difference that is mediated through the effects of rank on the age at first pregnancy. Additionally, females with later ages at slowing of crown-rump growth (indicating later attainment of adult height) are more likely to miscarry than those that slow growth at younger ages. Coupling miscarriage rates with infant death in the first two months of life, likelihood of failure for the first reproductive bout reaches 82.8%. Thus females must try to balance the timing of the first reproductive bout with growth rates to try to minimize this risk of failure.