Effect of dietary preformed water on energy and water budgets of two sympatric desert rodents, Acomys russatus and Acomys calzivinus
Article first published online: 8 JUL 2009
1993 The Zoological Society of London
Journal of Zoology
Volume 231, Issue 1, pages 51–59, September 1993
How to Cite
And, M. K. and Decen, A. A. (1993), Effect of dietary preformed water on energy and water budgets of two sympatric desert rodents, Acomys russatus and Acomys calzivinus. Journal of Zoology, 231: 51–59. doi: 10.1111/j.1469-7998.1993.tb05352.x
- Issue published online: 8 JUL 2009
- Article first published online: 8 JUL 2009
- (Accepted 28 July 1992)
Golden spiny mice (Acomys russatus) and common spiny mice (Acomys cahirinus) are omnivorous rodents that are sympatric in many rocky areas in Israeli deserts. They are similar in body size and diet habits. They differ in that A. cahirinus are nocturnal whereas A. russatus are diurnal and A. russatus inhabit extremely arid areas where A. cahirinus are absent. These differences led us to hypothesix that A. russatus are more conservative in their water needs and thererore are ahle to consumc a drier diet than A. chairinus. To test this hypothesis we oikrcd both species a dry ration and different numbers of snails and measured their energy and water intakes and their body mass changes.
Acomys russatus were capable of maintaining body mass on a much drier diet than A. cahirinus and therefore our hypothesis was supported. In order to maintain body mass A. cahirinus required about 2·1 ml/day (or about 4·7% body mass) preformed water, about twice the volume required by A. russatus. They also required a diet that had a water content of 48·3%, of the fresh matter, which was about 20% higher than that of A. russatus. The main reason why A. russatus needed less water was that they losl less by evaporation than A. cahirinus did. We suggest that the lower preformed water needs of A. russatus and their ability to consume a drier diet allom them to tolerate higher air temperatures and to inhabit extreme deserts where A. cahirinus are absent.