1) Large temperature differences have a measurable effect on ectothermic power consumption both at rest and during locomotion, yet this question remains to be satisfactorily addressed in ecological studies looking at optimal foraging strategy and performance. 2) Acclimation may influence the enzyme complement present in ectotherms and this could influence the energetic cost and efficiency of locomotion for ectotherms. 3) There may be an optimal temperature for ectothermic locomotion and this may vary from species to species, yet we measure power consumption during locomotion uniformly at 30?C. 4) Endothermic locomotion as demonstrated by birds is temperature sensitive,
as was shown by Paladino and King (1984). Although the locomotory cost may not change, thermoregulatory adaptations allow the bird to use the heat produced during locomotion in the cold to reduce thermoregulatory power requirements. 5) Avian hypothermia and inactivity is not a last ditch effort to save energy, but a strategy that allows endotherms to conserve energy reserves during inactivity or stressful environmental conditions.