Abstract # 104:

Scheduled for Friday, June 18, 2010 07:00 PM-09:00 PM: Session 18 (Medallion Ballroom C/D/E/F) Poster Presentation


EFFECTS OF NUMBER OF CLOSE RELATIVES ON INFANT DEVELOPMENTAL MILESTONES IN SOCIALLY HOUSED MACACA MULATTA

E. K. Mallott, N. A. Bowling, C. S. Ionica, E. A. Kerschner, M. L. Miller, M. S. Novak, K. L. Robbins and S. J. Suomi
Laboratory of Comparative Ethology - NICHD/NIH, NIH Animal Center, P.O. Box 529, Poolesville, MD 20837, USA
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Field studies of infant development in macaques often focus on the effects of immature siblings. The results of these studies are typically confounded by parity. In our study of mother-infant interactions, the number of close relatives (≤2 generational steps away) is not correlated with parity of the mother, due to selective weaning of offspring. We examined the effect the number of close relatives an infant has on developmental milestones indicating increasing independence from the mother. We predicted that infants with close relatives would reach developmental milestones earlier than those without. We tracked 28 milestones in 14 infants housed in either species-typical matrilines in a 5-acre outdoor enclosure [n=7], or smaller indoor/outdoor groups consisting of unrelated females and their offspring [n=7]. Consistent with studies focusing on siblings, the first time the mother restrains the infant is significantly later for infants with close relatives [Survival Analysis: α=0.05]. In contrast to previous studies, we found that infants, of primiparous and multiparous mothers, without close relatives are first left by the mother significantly earlier than other infants, and infants without close relatives tend to be >60cm from the mother at an earlier age. The contrast in independence levels at different ages between infants with and without close relatives may be due to differences in the social demands of mothers who have familial relationships and those who do not.