Food restriction affects the maternal behavior provided by female meadow voles (Microtus pennsylvanicus)


Many female small mammals face limited food availability during lactation. These dams may have to choose between altering the amount of maternal behavior they provide to their young, reducing the size of their litter, or not adjusting their behavior or litter size. How females allocate energy to maternal investment may depend on the energy costs of different lactation stages. We hypothesized that the amount of time female voles provided maternal behavior would differ if they were deprived of food during early, middle, or late lactation. We tested this hypothesis by placing lactating female meadow voles (Microtus pennsylvanicus) into 1 of 4 groups: dams that underwent a 30% caloric restriction during days 1-7 of lactation, those that were food restricted on days 8-14, those that were food restricted on days 15-21, and dams that did not undergo food restriction during lactation. Dams that were not food restricted spent more time engaged in maternal behavior than dams that were food restricted during lactation. Dams that were food restricted during days 8-14 of lactation displayed the most pronounced decline in maternal behavior relative to dams that were restricted during days 1-7 or days 15-21 of lactation. This effect was most dramatic in the amount of time that dams spent licking their pups. Reduced licking of pups may affect the mother-pup bond, inducing pups to possibly develop deficits in their social and sexual behavior as adults. The results also suggest that when they are faced with a food shortage, particularly during the 1st week of lactation, lactating female meadow voles do not reduce the size of their litter but do show a decrease in maternal behavior toward pups. © 2013 American Society of Mammalogists.

Publication Title

Journal of Mammalogy