Cooper, Christine Eliza

McAllan, Bronwyn Marie

Geiser, Fritz

2005

Metabolic rate and evaporative water loss (EWL) were measured for a small, arid-zone marsupial, the stripe-faced dunnart ('Sminthopsis macroura'), when normothermic and torpid. Metabolic rate increased linearly with decreasing ambient temperature (Ta) for normothermic dunnarts, and calculated metabolic water production (MWP) ranged from 0.85±0.05 (Ta=30°C) to 3.13±0.22 mg H2O g⁻¹ h⁻¹ (Ta=11°C). Torpor at Ta=11 and 16°C reduced MWP to 24–36% of normothermic values. EWL increased with decreasing Ta, and ranged from 1.81±0.37 (Ta=30°C) to 5.26±0.86 mg H2O g–1 h⁻¹ (Ta=11°C). Torpor significantly reduced absolute EWL to 23.5–42.3% of normothermic values, resulting in absolute water savings of 50–55 mg H2O h⁻¹. The relative water economy (EWL/MWP) of the dunnarts was unfavourable, remaining >1 at all Ta investigated, and did not improve with torpor. Thus torpor in stripe-faced dunnarts results in absolute, but not relative, water savings.

Journal of Comparative Physiology B, 175(5), p. 323-328

1432-136X

0174-1578

https://hdl.handle.net/1959.11/3082

Springer

Effect of torpor on the water economy of an arid-zone marsupial, the stripe-faced dunnart ('Sminthopsis macroura')

Journal Article

Publication