Reproductive Parameters and Maternal Investment in Mandrills (Mandrillus sphinx)
Source: International Journal of Primatology, Volume 23, Number 1, February 2002 , pp. 51-68(18)
Abstract:We report on 14 years of reproductive data for semifree-ranging mandrills (Mandrillus sphinx) in Gabon, and we explore relationships between female rank, age and parity, and reproductive strategies. Most births (61% of 132) occurred during the wet season in Gabon, between January and March. Female rank and parity were unrelated to the timing of parturition. Gestation lengths average 175 days (SE = ±1 day; N = 61) and were similar irrespective of female rank, parity, or sex of offspring. Birth sex ratio did not differ significantly from unity (52% male), and was unrelated to maternal rank or parity. Stillbirths and neonatal mortality tended to be more common among lower-ranking females than among either mid-ranking or dominant females. Median age at first birth is 4.71 years, at a median body mass of 7.6 kg, ca 5 years before females attain their adult body mass (median 12 kg). Age at first reproduction is significantly correlated with dominance rank, with dominant females giving birth on average 1.3 years earlier than lower-ranking females do. Interbirth intervals (IBI) average 405 days (range 184–1159 days, N = 103), and are independent of the sex of the offspring. Infant death within 6 months shortened IBI to 305 days. Increasing age and parity are also associated with short IBI, as is higher rank. Maternal rank and parity appear to influence reproductive success in female mandrills, but there is no apparent differential maternal investment by sex.
Document Type: Regular Paper
Affiliations: 1: Sub-Department of Animal Behaviour, University of Cambridge, Madingley, Cambridge CB3 8AA, U.K. 2: Department of Biological Anthropology, University of Cambridge, Downing Street, Cambridge CB2 3DZ, U.K.; firstname.lastname@example.org 3: Centre International de Recherches Médicales, B.P. 769, Franceville, Gabon 4: Centre for the Reproduction of Endangered Species, Zoological Society of San Diego, San Diego, California
Publication date: 2002-02-01