Growth velocity and weaning δ15N "Dips" during ontogeny in Macaca mulatta. Issue 2 (24th February 2015)

• Record Type: Journal Article
• Authors: Reitsema, Laurie J.; Muir, Andrew B.
• Is Part Of: American journal of physical anthropology. Volume 157:Issue 2(2015)
• Page Start: 347
• Page End: 357
• Publication Date: 2015-02-24
• Subjects: Physical anthropology -- Periodicals; Anthropology -- Periodicals; Anthropologie physique -- Périodiques; 599.9
• DOI: 10.1002/ajpa.22713
• Languages: English
• ISSNs: 0002-9483

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <sec id="ajpa22713-sec-0001" sec-type="section"> <title>Objectives:</title> <p>A "dip" in the stable nitrogen isotope ratios (δ<sup>15</sup>N) of subadults in the late weaning/early post‐weaning phase of growth and development has been observed. Speculatively, this is the mechanism of positive nitrogen balance operating among rapidly growing subadults. An alternate hypothesis for δ<sup>15</sup>N dips is that during weaning, subadults eat lower‐<sup>15</sup>N foods than adults.</p> </sec> <sec id="ajpa22713-sec-0002" sec-type="section"> <title>Methods:</title> <p>This study explores the role of positive nitrogen balance in affecting δ<sup>15</sup>N variation of growing subadults by comparing growth velocity with stable carbon isotope (δ<sup>13</sup>C) and δ<sup>15</sup>N ratios of blood serum from captive rhesus macaques (<italic>Macaca mulatta</italic>) (<italic>n</italic> = 14) with controlled diets during the first 10 months of life.</p> </sec> <sec id="ajpa22713-sec-0003" sec-type="section"> <title>Results:</title> <p>During the first six months, δ<sup>15</sup>N values are inversely correlated with growth in some of the anthropometrics (weight and sagittal circumference). Dips in some infants' δ<sup>15</sup>N values below their mothers' values are observed at the end of the weaning period. However, during this time frame, δ<sup>15</sup>N values of the infants are not correlated with anthropometric indices. Serum stable isotope ratios of lactating and non‐lactating adult females differ significantly.</p> </sec> <sec id="ajpa22713-sec-0004" sec-type="section"> <title>Conclusions:</title> <p>Growth in body mass and size explains some of the variation in infant δ<sup>15</sup>N values, but are not responsible for dips in the late weaning/early post‐weaning phase. It is advised that future research evaluate the extent to which growth in other body systems affects nitrogen balance and δ<sup>15</sup>N dips during ontogeny, and expand on isotopic differences between lactating and non‐lactating females. Am J Phys Anthropol 157:347–357, 2015. © 2015 Wiley Periodicals, Inc.</p> </sec> </abstract>