Evaporative water loss in seven species of fossorial rodents: Does effect of degree of fossoriality and sociality exist?

LUNA, FACUNDO; SUMBERA, RADIM; OKROUHLÍK, JAN; MLAD?NKOVÁ, NELLA; ANTENUCCI, C. DANIEL

JOURNAL OF THERMAL BIOLOGY

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2020 vol. 89

0306-4565

Interrestrial endotherms, evaporation is a significant mechanism of water loss inhot environments. Although water is passively lost by evaporation, individualscan regulate it at different levels. Inhabiting a relatively stable environmentcharacterized by mild ambient temperature (Ta) and high humidity canensure a balanced water budget. Many fossorial rodents are well adapted to livein such conditions. In this study, evaporative water loss (EWL) of fossorialrodent species with different degree of adaptations to underground life (fromstrictly subterranean to those with regular surface activity) was evaluated. Bymeasuring EWL, the specific contribution of either evaporative ornon-evaporative components of heat loss can be determined. With the exceptionof the silvery mole-rat (Heliophobius argenteocinereus), in all testedrodents EWL is relatively stable below and within the thermoneutral zone (TNZ).As Tas increase above TNZ, EWL increases as does total thermalconductance, but conductance increases several times more than EWL. Inaddition, non-evaporative routes seem to be more important than evaporativeheat loss in the analyzed species. No clear pattern of EWL in relation to aspecies degree of fossoriality or sociality was detected. In this context,atmosphere of burrows could affect EWL, since the high humidity found insidetunnels can establish limits on evaporation to favor water rather than thermalbalance.