Abstract # 1855 Event # 2:

Scheduled for Thursday, August 17, 2006 09:30 AM-09:45 AM: Session 1 (Regency East #1) Oral Presentation

Mating System and Costs of Infant Care across Neotropical Primate Taxa: A Bioenergetic Perspective

N. P. Rao
Oklahoma University Health Sciences Center, 2212 Pawnee Crossing, Edmond, OK 73034, USA
     This paper represents an attempt to elucidate the relationship between the cost of infant care and mating system as applied to Neotropical primate taxa. Although this question has been studied many times before, answers have tended to be ambiguous due to the use of heterogeneous types of data. This situation has resulted in researchers coming to opposite conclusions about the strength of a link between infant costs and mating system while looking at the same variables. For that reason, a new bioenergetic model was developed that combines physiological, developmental, and ecological variables to present cost of infant care as a unified measure: percent increase in Daily Energy Expenditure (DEE). This study used data from 28 species representing all four major radiations. Data on activity patterns was taken exclusively from field studies while developmental data was taken from both captive and wild sources. It was shown that: 1) Variation in cost of infant care is substantial (16%-133% increase in DEE). 2) Higher costs are correlated with paternal care (r2=0.76, p<0.01) and with monogamous and cooperative breeding mating systems (r2=0.91, p<0.01). 3) Carrying makes up a substantial proportion of total cost (11%-42%). And that 4) Relative paternal/sibling investment is higher in the aforementioned mating systems. This study found that not only is cost of infant care substantially higher in monogamous and cooperative breeding species, the brunt of these increased costs is borne by non-maternal caregivers.