Physiological Flexibility in Field Urine Osmolality of Rodents from Semi-Arid Chile

Francisco Bozinovic, Mauricio Lima, Leonardo D. Bacigalupe, Julio R. Gutiérrez, Mario Rosenmann and Arturo Cortés

in The Quintessential Naturalist

Published by University of California Press

Published in print July 2007 | ISBN: 9780520098596
Published online March 2012 | e-ISBN: 9780520916159 | DOI:
Physiological Flexibility in Field Urine Osmolality of Rodents from Semi-Arid Chile

Show Summary Details


This chapter assesses long-term physiological responses in field urine osmolality (Uosm) of four murid rodents from semi-arid Chile, as a function of the El Niño Southern Oscillation. It observes that all of the rodent species studied showed important temporal fluctuations in their Uosm-values, indicating both seasonal and annual patterns of physiological variability characterized by high Uosm-values during the Austral spring–summer and low Uosm-values during autumn–winter. The chapter further observes significant effects of year and season on Uosm-values, with a year x season interaction. It demonstrates how flexibility of physiological mechanisms allows small mammals in arid or semi-arid regions to cope with long-term seasonal and annual water variability in their semi-arid habitat. The chapter notes that the trends of seasonal water balance during contrasting years (i.e., El Niño vs. dry years) is likely to be a consequence of plant cover, since this is the principal food and water source of rodents at Fray Jorge.

Keywords: physiological responses; field urine osmolality; rodents; Chile; El Niño; small mammals; habitat; plant cover; Fray Jorge

Chapter.  4580 words.  Illustrated.

Subjects: Zoology and Animal Sciences

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.