Tradeoffs between quality of offspring and litter size: Differences do notpersist into adulthood

Persistent effects of the tradeoff between number and size of offspring per litter were examined by comparing mean mass of northern grasshopper mice ( Onychomys leucogaster) within litters at the end of complete maternal depen dence (age 16 days), at separation from mothers (28 days), and as adults (6 0 days). Although there was a significant effect of lifter size on mean mas s of offspring early in lactation, young showed compensatory growth as soon as they began eating solid food. No difference in body size was evident at weaning or among adults. Compensatory growth was fueled by increased consu mption of food relative to body mass; smaller offspring in large litters co nsumed as much food per capita as large offspring from small litters. To th e extent that body size can influence reproductive potential, the offspring 's capacity for compensatory growth suggests that much of the penalty for l arge litters is through decreased recruitment or through reduced future rep roduction by mothers rather than differences in reproductive potential of o ffspring as adults.