Meeting Abstract

P3.16  Thursday, Jan. 6  Association between high daily energy expenditures (DEE) and winter mortality in Root vole Microtus oeconomus SZAFRANSKA, Paulina A*; ZUB, Karol; SPEAKMAN, John R; KONARZEWSKI, Marek; Mammal Research Institute Polish Academy of Sciences; Mammal Research Institute Polish Academy of Sciences; The University of Aberdeen; Mammal Research Institute Polish Academy of Sciences pszafran@zbs.bialowieza.pl

Traditionally, energy supply is considered to be a limiting factor in animal’s energy budget. However, it is possible that the upper boundary of energy expenditure is set by the maximal capacity to dissipate body heat, rather than energy supply. To test this, we increased heat loss of free living Root voles by shaving their back and compared their Daily Energy Expenditures (DEE) and resting metabolic rate (RMR) with free-living control individuals from the same location in the fall of 2008 and 2009, differing with respect to an ambient temperature. DEE and RMR were significantly affected by body mass and year, but not the effect of shaving. DEE and RMR were not significantly correlated either within control, nor shaved animals, or across treatments. Our preliminary results suggest that free living Root voles are capable of compensating an increased heat loss by changes in behavior.