Thermoregulation by an Australian murine rodent, the ash-grey mouse (Pseudomys albocinereus)

Author(s)

Barker, Justine M. ^[1] ; Cooper, Christine E. ^{[1, 2]} ; Withers, Philip C. ^{[1, 2]} ; Cruz-Neto, Ariovaldo P. ^{[1, 2, 3]}

Affiliation

^[1] Curtin Univ Technol, Dept Environm & Agr, Perth, WA 6845 - Australia

^[2] Univ Western Australia, Sch Anim Biol, Crawley, WA 6009 - Australia

^[3] UNESP Rio Claro, IB, Dept Zool, BR-13506900 Rio Claro, SP - Brazil

• Document type: Journal article
• Source: COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY; v. 163, n. 3-4, p. 336-342, NOV 2012.
• Web of Science Citations: 9

Abstract

We examine here the thermal physiology of the ash-grey mouse, as there is a paucity of data to explain how Australian rodents meet thermoregulatory demands. Most ash-grey mice remained normothermic over a range of ambient temperatures (10 degrees C to 30 degrees C), although they became hyperthermic at high ambient temperatures. One individual entered torpor at ambient temperatures of 20 degrees C and 25 degrees C, with minimal body temperatures of 24.5 degrees C and 28.4 degrees C respectively, before spontaneously arousing. This is the first evidence of torpor use by an Australian murine rodent. Our data suggest that although ash-grey mice have the physiological ability to use torpor, it is used rarely, presumably due to other behavioural and physiological adaptations. Their higher-than-expected basal metabolic rate (1.56 +/- 0.25 mL O-2 g(-1) h(-1)) indicates that ash-grey mice do not have a frugal approach to energy expenditure. Other standard physiological variables were typical of a generalised rodent. A readily-available omnivorous diet, nocturnal activity, semi-fossorial habit and social behaviour presumably allow a high energy lifestyle. A reluctance to use torpor, despite an apparent physiological ability to do so, supports the idea that the use of torpor reflects a net balance between the costs and benefits of a heterothermic thermoregulatory strategy. (C) 2012 Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 07/02837-4 - Integrative analysis of the energetic and hydric patterns in marsupials
• Grantee: Ariovaldo Pereira da Cruz-Neto
• Support Opportunities: Scholarships abroad - New Frontiers