Variation in maternal strategies during lactation: The role of the biosocial context

mentioning

confidence: 98%

Growth velocity and weaning δ¹⁵N “Dips” during ontogeny in Macaca mulatta

Reitsema

Muir

2015

“…Not only is there extreme variation between and within particular societies, but offspring are typically weaned at much earlier ages than non-human primates, such as great apes. For example, accounting for differences in growth rates and life history effects, humans breastfeed on average less than half as long as our close relatives, chimpanzees and gorillas (Dettwyler, 2004;Kennedy, 2005).Early human weaning and the nature of early childhood diets, as well as high interindividual variation in such practices, has been used to speculate on a number of evolutionary processes in our species' past (Trivers, 1974;Blurton-Jones, 1986;Sellen and Smay, 2001, Stearns, 1992;Kaplan, 1996;Borgerhoff-Mulder, 1992, 2001Piperata, 2009). These processes often pit the costs of longer breastfeeding to parents, especially mothers, against benefits to offspring.…”

mentioning

confidence: 99%

“…Early human weaning and the nature of early childhood diets, as well as high interindividual variation in such practices, has been used to speculate on a number of evolutionary processes in our species' past (Trivers, 1974;Blurton-Jones, 1986;Sellen and Smay, 2001, Stearns, 1992;Kaplan, 1996;Borgerhoff-Mulder, 1992, 2001Piperata, 2009). These processes often pit the costs of longer breastfeeding to parents, especially mothers, against benefits to offspring.…”

mentioning

confidence: 99%

Sex‐biased weaning and early childhood diet among middle holocene hunter–gatherers in Central California

Eerkens

Bartelink

2013

102

This article evaluates age of weaning and early childhood diets of eight males and nine females from a Middle Holocene (4300-3000 BP) site in Central California, CA-CCO-548. All individuals died as adults. d 15N values from serial sections of dentin collagen in first molars suggest females were fully weaned, on average, by 3.6 years of age, about 0.4 years later than males in the sample, suggesting possible greater parental investment in female offspring. However, throughout childhood females consumed lower trophic-level foods than males. This could indicate greater investment in males through provisioning of higher quality foods, or alternatively, some degree of independent foraging by males starting as early as 2 to 3 years of age. Even as adults, these same males and females consumed a different range of foods as indicated by their bone collagen d Humans are unique among primates in terms of child investment and weaning practices. Not only is there extreme variation between and within particular societies, but offspring are typically weaned at much earlier ages than non-human primates, such as great apes. For example, accounting for differences in growth rates and life history effects, humans breastfeed on average less than half as long as our close relatives, chimpanzees and gorillas (Dettwyler, 2004;Kennedy, 2005).Early human weaning and the nature of early childhood diets, as well as high interindividual variation in such practices, has been used to speculate on a number of evolutionary processes in our species' past (Trivers, 1974;Blurton-Jones, 1986;Sellen and Smay, 2001, Stearns, 1992;Kaplan, 1996;Borgerhoff-Mulder, 1992, 2001Piperata, 2009). These processes often pit the costs of longer breastfeeding to parents, especially mothers, against benefits to offspring. Breast milk is a significant energetic investment for a mother. It can negatively impact her health, require her to work harder to obtain calories, take away from time she could be working (opportunity costs), and decrease her ability to get pregnant again, lowering her fertility and overall fitness, as well as that of her male partner (Delgado et al., 1982;Borgerhoff-Mulder, 1992;Riordan, 2005;Sellen, 2006;Piperata and Mattern, 2011). On the other hand, breast milk provides a child with a reliable and easily digestible source of calories and nutrients. Empirical evidence suggests that extended breastfeeding offers long-term benefits to children, such as increased stature, better cognitive capabilities (e.g., higher IQ), greater immunity to some diseases, and lower rates of obesity (Taren and Chen, 1993; Mortensen et al., 2002;Schack-Nielsen and Michaelsen, 2006), effects also seen in non-human primates (Hinde et al., 2009). For these reasons, the age at which a mother weans a child has often been used as a proxy measure of parental investment in offspring (Stuart-Macadam and Dettwyler, 1995;Humphrey, 2010).Research in human behavioral ecology suggests that parents will reduce their investment in children in environments where increas...

“…Small sample size limits our ability to fully explain the inter‐individual variation in breastfeeding patterns observed among these Ribeirinha women, as well as the consequences of their individual strategies. However, the detailed longitudinal data reported here, along with similarly detailed data on the women's dietary intakes and energy expenditure patterns reported in previous publications (Piperata and Dufour, 2007; Piperata, 2009) do allow us to explore at least some of the potential costs and benefits associated with their strategies.…”

Section: Discussionmentioning

confidence: 64%

Longitudinal study of breastfeeding structure and women's work in the Brazilian Amazon

Piperata

Mattern

2010

Self Cite

It is well established that breast milk is the ideal food for infants and that breastfeeding has short- and long-term health benefits for the mother and child. However, there is variation in breastfeeding patterns between populations. Women's work is thought to influence breastfeeding patterns and timing of supplementation and it is often assumed that women in subsistence-oriented societies can more easily integrate their productive and reproductive activities. This article reports longitudinal data, collected in three rounds (resguardo [<40 days], peak [2-4 months], and late [14-16 months] lactation), on breastfeeding structure, infant care, and work patterns of 17 rural Amazonian women in an effort to understand how breastfeeding structure and maternal time allocation changed over time, as well as the strategies women used to integrate their productive and reproductive roles. Women breastfed 10.6 ± 3.1, 9.4 ± 3.4, and 9.6 ± 5.5 times per 9-h period in the three rounds, respectively. Breastfeeding structure, specifically session duration, changed over time (P < 0.05). As lactation progressed, women spent less time breastfeeding and in infant care and more time in subsistence work. In peak lactation, subsistence work was negatively correlated with infant care (r = -0.4, P = 0.01), breastfeeding (r = -0.29, P = 0.05) and session duration (r = -0.39, P < 0.01) and in late lactation was negatively correlated with time spent breastfeeding (r = -0.39, P < 0.01) and in infant care (r = -0.50, P < 0.01) and positively correlated with inter-session interval (r = 0.40, P < 0.01). Generally, women reduced time in subsistence work when breastfeeding was more intense and returned to normal activity patterns once infants were being supplemented. The costs and benefits associated with women's strategies are discussed.