Aerobic capacity and running performance across a 1.6 km altitude difference in two sciurid rodents

摘要: Hypoxia at high altitudes is often assumed to constrain exercise capacity, but there have been few high- versus low-altitude comparisons of species native a wide range altitudes. Such studies are ecologically realistic, as wild-caught animals tested their altitude presumably maximally acclimated (via phenotypic plasticity) or adapted (by evolutionary change) that altitude. We compared aerobic performance, measured maximum oxygen consumption in forced (V(O(2),max)), and voluntary wheel-running two sciurid rodents captured field sites differed by 1.6 km (2165 m 3800 m). found reduced V(O(2),max) least chipmunks (Tamias minimus) no significant effect on golden-mantled ground squirrels (Spermophilus lateralis). Individuals both averaged several day(-1) wheels. Most behavioral indices running (including mean speeds, time spent running, daily distance, the number duration bouts) were unaffected altitude, even with Metabolic rates during energy costs transport some extent across different ways species. At test sites, was almost exclusively speeds well within limits. conclude substantial differences do not necessarily result capacity small mammals and, if may be behavior.