TY - JOUR
T1 - Offspring of primiparous mothers do not experience greater mortality or poorer growth
T2 - Revisiting the conventional wisdom with archival records of Rhesus Macaques
AU - Nuñez, Chase L.
AU - Grote, Mark N.
AU - Wechsler, Michelle
AU - Allen-Blevins, Cary R.
AU - Hinde, Katie
N1 - Publisher Copyright:
© 2015 Wiley Periodicals, Inc.
PY - 2015/9/1
Y1 - 2015/9/1
N2 - Female mammals often begin to reproduce before achieving somatic maturity and therefore face tradeoffs between allocating energy to reproduction or their own continued development. Constraints on primiparous females are associated with greater reproductive failure, and first-born infants often have slower growth and greater mortality and morbidity than infants born to multiparous females. Effects of early life investment may persist even after weaning when juveniles are no longer dependent on maternal care and mother's milk. We investigated the long-term consequences of birth order in a large sample of rhesus macaques, Macaca mulatta, assigned to the outdoor breeding colony at the California National Primate Research Center (n=2, 724). A joint model for growth and mortality over the first three years of life allowed us to explicitly connect growth rates to survival. As expected, males are born heavier and grow faster relative to females. However, contrary to expectations, later-born males face substantially lower survival probability during their first three years, whereas first-born males survive at greater rates similar to both first-born and later-born females. Primiparous mothers are less likely to conceive during the subsequent breeding season, suggesting that their reproductive costs are greater than those of multiparous mothers. We speculate that compensatory tactics, both behavioral and physiological, of first-born offspring and their mothers, as well as the novel ecology of the captive environment, underlie these findings. The results presented here provide new insights into how maternal and infant life history tradeoffs may influence developmental trajectories even after the period of maternal dependence. Am. J. Primatol. 77:963-973, 2015.
AB - Female mammals often begin to reproduce before achieving somatic maturity and therefore face tradeoffs between allocating energy to reproduction or their own continued development. Constraints on primiparous females are associated with greater reproductive failure, and first-born infants often have slower growth and greater mortality and morbidity than infants born to multiparous females. Effects of early life investment may persist even after weaning when juveniles are no longer dependent on maternal care and mother's milk. We investigated the long-term consequences of birth order in a large sample of rhesus macaques, Macaca mulatta, assigned to the outdoor breeding colony at the California National Primate Research Center (n=2, 724). A joint model for growth and mortality over the first three years of life allowed us to explicitly connect growth rates to survival. As expected, males are born heavier and grow faster relative to females. However, contrary to expectations, later-born males face substantially lower survival probability during their first three years, whereas first-born males survive at greater rates similar to both first-born and later-born females. Primiparous mothers are less likely to conceive during the subsequent breeding season, suggesting that their reproductive costs are greater than those of multiparous mothers. We speculate that compensatory tactics, both behavioral and physiological, of first-born offspring and their mothers, as well as the novel ecology of the captive environment, underlie these findings. The results presented here provide new insights into how maternal and infant life history tradeoffs may influence developmental trajectories even after the period of maternal dependence. Am. J. Primatol. 77:963-973, 2015.
KW - Joint growth and survival model
KW - Maternal investment
KW - Primiparity
KW - Sex bias
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U2 - 10.1002/ajp.22426
DO - 10.1002/ajp.22426
M3 - Article
AN - SCOPUS:84939574428
SN - 0275-2565
VL - 77
SP - 963
EP - 973
JO - American Journal of Primatology
JF - American Journal of Primatology
IS - 9
ER -