The ability to control body temperature enables endotherms to live in cold or thermally variable environments yet remain active. On a geographical scale, endotherms can live in regions too cold for most ectotherms. On a temporal scale, endotherms can be active year-round in regions with cold seasons, as well as be active during cold parts of the day or night. Endotherms not only have high SMR, RMR, and FMR, they also have high aerobic capacities (maximal aerobic metabolism). These high aerobic capacities make it possible to sustain vigorous activity for extended time periods. As a result, endotherms can maintain large territories and migrate for long distances.
While there are diverse benefits of endothermy, endothermy also has costs. In particular, endotherms have higher metabolic rates than ectotherms (Figure 3), so they must locate and process more food to provide the energy to sustain higher metabolism. Typically, an endotherm requires much more energy and food than a similar-sized ectotherm (Table 2). The cost of endothermy relative to ectothermy changes with environmental temperature. At warm environmental temperatures, the energetic cost of endothermy relative
Was this article helpful?