ABSTRACT. Two species of galagos (G. senegalensis moholi and G. garnettii) were subjected to dehydration and starvation stress in order to determine whether, as is common in other animals, these hypometabolic prosimians would lower their metabolic rate even further. Dehydration was confirmed by losses in body mass, a decrease in fecal water content and a rise in urine osmolality. At the height of dehydration, 20 to 25 ~ reduction in body mass, 30 to 40 ~ reduction in fecal water content and urine osmolality ranging from 1.8 to 3.50smol kg -1 HzO, were recorded in some of the animals. Basal metabolic rate of 0.536 ml O~ (g'h) -1 in G. s. moholi and 0.302 ml O~ (g'h) -t in G. garnettii were recorded, representing 50 to 42 ~ reduction in metabolic rate, respectively, compared with mass specific values. In none of the tested animals did we observe significant reduction in basal metabolism during dehydration/starvation stress compared with the rates observed during the control period. Basal metabolism in the bushbabies seems to have reached the lowest level and no further adjustment is apparently possible as a strategy for energy saving during starvation and/or dehydration stress.