Hoole, C; Czenze, Zenon J; Bennett, N C; McKechnie, A E

Author(s)

Hoole, C

Czenze, Zenon J

Bennett, N C

McKechnie, A E

Publication Date

2019

Abstract

Small mammals, and particularly shrews and mice, have relatively high mass-specific metabolic rates and may be constrained to habitats where they can avoid extreme temperatures. Although their phylogeny differs, shrews and rodents often inhabit the same environments and compete for resources due to their similar body masses and dietary overlap. Our aim was to elucidate the variation in thermal parameters of sympatric species. We examined Myosorex varius, Crocidura flavescens and Mus minutoides, by measuring metabolic rate, evaporative water loss (EWL), body temperature (Tb) and thermal conductance over a range of ambient temperatures (Ta). Body temperatures of all three species remained above 32°C across the range of Ta. For all species, there was no relation between Ta <35°C and EWL, although EWL in C. flavescens was considerably lower compared to the other two species. Dry thermal conductance was much higher in Mu. minutoides than in either of the shrews. Resting metabolic rate of all three species declined with Ta <35°C. The thermoneutral zone of My. varius was between Ta = 35°C and Ta = 40°C, whereas that of C. flavescens was between Ta = 30°C and Ta = 33°C. No discernible thermoneutral zone was evident for Mu minutoides. Our data reveal considerable variation in thermal physiology among three sympatric species of small mammal at a single site and generally conform to the plesiomorphic–apomorphic endothermy model. Differences in body size, life-history traits and evolutionary history may all play a role in the thermoregulatory patterns of these sympatric species.

Citation

Journal of Zoology, 307(1), p. 28-35

ISSN

1469-7998

0952-8369

Link

https://hdl.handle.net/1959.11/61278

Publisher

Wiley-Blackwell Publishing Ltd

Title

Thermal physiology of three sympatric small mammals from southern Africa

Type of document

Journal Article

Entity Type

Publication

Author(s)	Hoole, C Czenze, Zenon J Bennett, N C McKechnie, A E
Publication Date	2019
Abstract	<p>Small mammals, and particularly shrews and mice, have relatively high mass-specific metabolic rates and may be constrained to habitats where they can avoid extreme temperatures. Although their phylogeny differs, shrews and rodents often inhabit the same environments and compete for resources due to their similar body masses and dietary overlap. Our aim was to elucidate the variation in thermal parameters of sympatric species. We examined <i>Myosorex varius</i>, <i>Crocidura flavescens</i> and <i>Mus minutoides</i>, by measuring metabolic rate, evaporative water loss (EWL), body temperature (T<sub>b</sub>) and thermal conductance over a range of ambient temperatures (T<sub>a</sub>). Body temperatures of all three species remained above 32°C across the range of T<sub>a</sub>. For all species, there was no relation between T<sub>a</sub> <35°C and EWL, although EWL in <i>C. flavescens</i> was considerably lower compared to the other two species. Dry thermal conductance was much higher in <i>Mu. minutoides</i> than in either of the shrews. Resting metabolic rate of all three species declined with T<sub>a</sub> <35°C. The thermoneutral zone of <i>My. varius</i> was between T<sub>a</sub> = 35°C and T<sub>a</sub> = 40°C, whereas that of <i>C. flavescens</i> was between T<sub>a</sub> = 30°C and T</sub>a</sub> = 33°C. No discernible thermoneutral zone was evident for <i>Mu minutoides</i>. Our data reveal considerable variation in thermal physiology among three sympatric species of small mammal at a single site and generally conform to the plesiomorphic–apomorphic endothermy model. Differences in body size, life-history traits and evolutionary history may all play a role in the thermoregulatory patterns of these sympatric species.</p>
Citation	Journal of Zoology, 307(1), p. 28-35
ISSN	1469-7998 0952-8369
Link	https://hdl.handle.net/1959.11/61278
Publisher	Wiley-Blackwell Publishing Ltd
Title	Thermal physiology of three sympatric small mammals from southern Africa
Type of document	Journal Article
Entity Type	Publication

Thermal physiology of three sympatric small mammals from southern Africa

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