Endothermic animals have a basal, or minimal, rate of metabolism (basal metabolic rate; BMR) when they are post-absorptive, asleep in the rest-phase of their daily cycle, exposed to thermoneutral temperatures, and not engaged in energetically demanding life-history stages. Thus, the BMR represents an individual's baseline costs of maintaining vital functions . Metabolic measurements made under the same conditions but at times associated with elevated maintenance costs, such as during moult, during the day, or at temperatures outside the thermoneutral zone are termed RMR. Thus, BMR and RMR are pertinent reflections of the energetic costs of physiological processes at particular life-history stages and, thus, can be used to quantify the contemporaneous energy costs of parasite infections. Surprisingly, studies examining the effects of endoparasitic or ectoparasitic infection on host RMR are inconsistent, finding lower, higher or unchanged RMR owing to parasitic infections (reviewed in ). However, even if infections have minimal effect on an animal's maintenance metabolism, they could still limit their host's capacity for intense aerobic activities . Reduced aerobic capacity would be especially deleterious for long-distance flyers, as such flight requires sustained delivery and uptake of oxygen at high rates .