Food hoarding is increased by pregnancy, lactation, and food deprivation in Siberian hamsters

Food hoarding by male Siberian hamsters (Phodopus sungorus sungorus) is increased only when body mass (fat) is decreased. Pregnancy and lactation result in marked decreases in lipid reserves (similar to 50%) in female Siberian hamsters. Therefore, the present experiments addressed the following questions: 1) Is food hoarding increased after food deprivation in female Siberian hamsters? and 2) How do food hoarding and food intake change during pregnancy, lactation, and their combination? During measurements in a simulated burrow system, food hoarding increased after a 32-h fast (similar to 2- to 3-fold) to a level similar to that seen previously in males and was markedly increased during pregnancy (similar to 12- to 18-fold), lactation, and concurrent pregnancy and lactation (similar to 10- to 25-fold for each of the latter 2 conditions). Postfast food intake was not different from prefast baseline measures. Food intake was increased only during the last few days of pregnancy and was elevated throughout lactation. These impressive increases in the level of food hoarding during pregnancy, lactation, and their combination suggest that food hoarding may play an important role in supplying easily accessible energy to subserve these reproductive conditions.