Torpor is not the only option: seasonal variations of the thermoneutral zone in a small primate.

摘要: The reddish-gray mouse lemur (Microcebus griseorufus) is one of only a few small mammals inhabiting the spiny forest southwestern Madagascar. In this study we investigated physiological adjustments which allow these primates to persist under challenging climatic conditions their habitat. To end measured energy expenditure (metabolic rate) and body temperature 24 naturally acclimatized lemurs, kept in outdoor enclosures, during different seasons (summer, winter, and the transition period between the two seasons). Mouse lemurs displayed main strategies compensate seasonal diurnal fluctuations ambient temperature. On hand, individuals entered hypometabolism with decreasing (T a) enabling them save up 21 % per day (92 % hour) compared normal resting metabolic rate at comparable T a. other euthermic also showed seasonality when resting: lower critical thermoneutral zone decreased from summer winter by 7.5 °C, allowed keep demands constant despite colder as winter. addition, basal was substantially lowered prior period, facilitated accumulation fat reserves. combination modifications euthermia addition hypometabolism, can be individually adjusted according external parameters respective condition, important it allows M. griseorufus cope environmental variability an energetically