TY - JOUR
T1 - Opportunistic mothers
T2 - Female marmosets (Callithrix kuhlii) reduce their investment in offspring when they have to, and when they can
AU - Fite, Jeffrey E.
AU - Patera, Kimberly J.
AU - French, Jeffrey A.
AU - Rukstalis, Michael
AU - Hopkins, Elizabeth C.
AU - Ross, Corinna N.
N1 - Funding Information:
This study was a portion of the dissertation research of J.E. Fite in the Department of Psychology at the University of Nebraska at Omaha. The research presented here was described in Animal Research Protocol No. 95-103-07, and was approved by the Institutional Animal Care and Use Committee of the University of Nebraska Medical Center/University of Nebraska at Omaha. Financial support for this project was provided by grants from the National Science Foundation (IBN 97-23842 and 00-91030), the National Institute of Child Health and Development (HD 42882), and from the University of Nebraska at Omaha's Animal Care Fund.
PY - 2005/7
Y1 - 2005/7
N2 - All female primates incur energetic costs associated with producing and caring for offspring, but females belonging to the New World primate family Callitrichidae, the marmosets and tamarins, appear to face even further demands. In fact, the energetic demands of rearing callitrichid infants are thought to have led to the evolution of cooperative infant care in these species. If this explanation is true, then one might expect that natural selection should also have shaped patterns of maternal behavior to be sensitive to the costs of reproduction and equipped females to reduce their investment in offspring under certain conditions. Therefore, we examined the maternal effort and postpartum endocrine profiles of individual female marmosets (Callithrix kuhlii) across conditions that represented two hallmarks of callitrichid reproduction - conception during the early postpartum period and alloparental assistance. When females conceived during the early postpartum period and faced the upcoming demands of caring for their newly conceived litters (Study 1), they significantly reduced their caregiving effort and had significantly higher postpartum levels of estradiol relative to breeding attempts in which conception occurred later in the postpartum period. Postpartum estradiol was negatively correlated with maternal carrying effort. When experienced alloparents were present (Study 2), females again reduced their caregiving effort relative to breeding attempts in which experienced alloparents were not present. Postpartum cortisol, however, did not vary as a function of experienced alloparental assistance. The results of these studies suggest that female marmosets have been subjected to similar selection pressures as females of other primate taxa - to maximize their reproductive success by reducing their investment in offspring under the worst and best of conditions - and suggest that hormones may mediate within-female variation in maternal care. These studies also provide support for the notion that mothers are "flexible opportunists" when it comes to providing care to their young.
AB - All female primates incur energetic costs associated with producing and caring for offspring, but females belonging to the New World primate family Callitrichidae, the marmosets and tamarins, appear to face even further demands. In fact, the energetic demands of rearing callitrichid infants are thought to have led to the evolution of cooperative infant care in these species. If this explanation is true, then one might expect that natural selection should also have shaped patterns of maternal behavior to be sensitive to the costs of reproduction and equipped females to reduce their investment in offspring under certain conditions. Therefore, we examined the maternal effort and postpartum endocrine profiles of individual female marmosets (Callithrix kuhlii) across conditions that represented two hallmarks of callitrichid reproduction - conception during the early postpartum period and alloparental assistance. When females conceived during the early postpartum period and faced the upcoming demands of caring for their newly conceived litters (Study 1), they significantly reduced their caregiving effort and had significantly higher postpartum levels of estradiol relative to breeding attempts in which conception occurred later in the postpartum period. Postpartum estradiol was negatively correlated with maternal carrying effort. When experienced alloparents were present (Study 2), females again reduced their caregiving effort relative to breeding attempts in which experienced alloparents were not present. Postpartum cortisol, however, did not vary as a function of experienced alloparental assistance. The results of these studies suggest that female marmosets have been subjected to similar selection pressures as females of other primate taxa - to maximize their reproductive success by reducing their investment in offspring under the worst and best of conditions - and suggest that hormones may mediate within-female variation in maternal care. These studies also provide support for the notion that mothers are "flexible opportunists" when it comes to providing care to their young.
KW - Alloparental care
KW - Callitrichidae
KW - Lactation
KW - Maternal care
KW - Postpartum conception
KW - Wied's black tufted-ear marmoset
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U2 - 10.1016/j.jhevol.2005.04.003
DO - 10.1016/j.jhevol.2005.04.003
M3 - Article
C2 - 15935439
AN - SCOPUS:21244458768
VL - 49
SP - 122
EP - 142
JO - Journal of Human Evolution
JF - Journal of Human Evolution
SN - 0047-2484
IS - 1
ER -