Comparative water economy of sympatric rodents in a Chilean semi-arid habitat.
1. Water requirements, water balance components and dependence on exogenous water were estimated in four species of sympatric rodents inhabiting a Chilean semi-arid region. 2. A significant increase in free water drinking was observed in all rodents when the diet composition was changed from 14 to 20% protein. 3. Under water balance conditions the cricetid species (Phyllotis darwini, Oryzomys longicaudatus and Akodon olivaceus) showed 1.66 to 1.88 times the weight-specific daily water gain of Octodon degus. 4. In the three cricetid rodents, evaporation was the largest water loss component (2/3 to 3/4 of total loss), while in O. degus evaporative water loss amounted to only 38% of the total. 5. Survival time during water deprivation ranged from 13.4 days in O. degus to only 4 days in O. longicaudatus. 6. All water variables combined indicate that water dependence of O. longicaudatus greater than P. darwini greater than A. olivaceus greater than O. degus.
Cortes
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A
Departamento de Biología, Universidad de la Serena, Chile.
Zuleta
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C
Rosenmann
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M
D000818:Animals; D002677:Chile; D002980:Climate; D004326:Drinking; D012377:Rodentia / Q000502:physiology*; D014868:Water Deprivation / Q000502:physiology*