The social cost of reproduction to female Lemur catta

1 page.Though large variations of social dominance systems exist across primate species, ring-tailed lemurs (L. catta) exhibit a strong hierarchy with females ranking higher than males. Studies suggest this is due to the high cost of reproduction in a seasonal resource availability environment. Typically viewed as a species-level adaptation, these same evolutionary principles should hold on the individual level. As such, females with infants should experience higher reproduction-related costs than do females without infants, and therefore may show different behavioral strategies that reflect this cost differential. Data on affiliative and aggressive social behavior were collected during focal sampling in 1996 from two semi-free ranging L. catta groups at the Duke Lemur Center in Durham, NC. We compared interactions involving females with infants (N=5) to interactions that involve females without infants (N=4). We calculated rates based on the observation time (28.25 hrs). Females were more aggressive with an infant (0.74/hr) compared to those without (0.25/hr). In contrast, females without infants (3.58/hr) were more affiliative than those with infants (1.10/hr). These findings point to different behavioral strategies based on reproductive status in this taxon, depicting that females with infants suffer higher costs and have less ability to invest in sociality. L. catta’s sociality and behavior may explain these patterns, offering insight into how they compare to other primates