SEASONAL DIFFERENCES IN FIELD METABOLISM, WATER REQUIREMENTS, AND FORAGING BEHAVIOR OF FREE-LIVING AARDWOLVES

Abstract

Aardwolves occur in east-central and southern Africa in regions of arid and semiarid grasslands. In South Africa, they feed almost exclusively on the termite Trinervitermes trinervoides during the warmer months of the year, whereas on cold winter nights these insects remain belowground, unavailable to aardwolves. At this time aardwolves shift their foraging efforts to a less abundant termite species, Hodotermes mossambicus. This species provides less food for aardwolves, making the wintertime potentially a period of energy stress for them. In this study, we report the first estimates of field metabolism and water flux as determined by doubly labeled water for a myrmecophagous euthermic mammal. Specifically, we tested the hypotheses that a reduced basal metabolic rate and pulmocutaneous water loss lead to a conservative field metabolic rate (FMR) and water flux in free-living aardwolves during summer and winter. Further, we quantified the activity budget of aardwolves during summer and winter to construct ...