Characterizing the thermal environment of small mammals: what should we be measuring, and how?
Joy C Coleman, Colleen T Downs
School of Biological and Conservation Sciences, Scottsville, Pietermaritzburg, South Africa
Abstract: Operative temperature and standard operative temperature have been proposed as providing an estimate of the thermal load experienced by endotherms and ectotherms. Common techniques of measuring operative temperature include black-bulb temperatures or simplified unheated metal models, typically made of copper. We quantified the thermal environment perceived by a small, arboreal rodent using a number of methods at three study sites in winter and summer. Our area of interest was how well these methods accurately portrayed the actual temperatures that small mammals are exposed to. We predicted that black-bulb and copper model temperatures would more accurately predict operative temperature during photophase when compared with other direct measurements/devices, and that black-bulb temperature would record the greatest variation in temperatures. Temperature differences between the methods were largest during the midday, when temperatures were highest. All methods recorded a greater range of temperatures during photophase than during scotophase. Black-bulb and model temperatures produced more accurate, rapid measurements when compared with measurements produced by direct temperature recording devices, particularly during photophase, when solar radiation is the major influence of heating. Other methods lagged behind black-bulb measurements. Although mean temperatures of some of the methods were significantly different, there was a high degree of correlation between all methods, even after randomization and generation of 25% and 10% subsamples. In studies requiring accurate time series measurements, it is suggested that black-bulb or copper models be employed rather than direct temperature recording devices. Simpler measurement devices would suffice for studies requiring an estimate of the temperature variation and trends in the microclimate of small mammals, particularly arboreal or cavity dwelling species.
Keywords: ambient temperature, operative temperature, black-bulb, model, small mammal, cavity dweller
This work is published by Dove Medical Press Limited, and licensed under Creative Commons Attribution - Non Commercial (unported, v3.0) License. The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. Permissions beyond the scope of the License are administered by Dove Medical Press Limited. Information on how to request permission may be found at: http://www.dovepress.com/permissions.php
Readers of this article also read:
Pfeiffer N, Ebner J, von Thaden AK, Schuster T, Erhardt W, Baumgartner C
Published Date: 17 October 2012
Mansour AM, Shahin M, Kofoed PK, Parodi MB, Shami M, Schwartz SG
Published Date: 6 March 2012
Edwards JA, Mathes DW
Published Date: 5 September 2011
Oral glucose supplementation improved semen quality and constituents of seminal and blood plasma of NZW buck rabbits in the subtropics
Youssef A Attia, A E Abd El Hamid, Fulvia Bovera, et al
Published Date: 18 November 2010
Petra Quillfeldt, Maud Poisbleau, Ingrid Schwabl, et al
Published Date: 13 October 2010
S Begum, MMR Howlader, MS Islam, et al
Published Date: 19 August 2010
Bernadette Earley, Kelly Buckham-Sporer, Sandeep Gupta, et al
Published Date: 4 August 2010
Minoru Yamaoka, Yusuke Ono, Masahiro Takahashi, Ryosuke Doto, et al.
Published Date: 14 April 2009
Roger M Pinder
Published Date: 4 February 2009
Problems and barriers of pain management in the emergency department: Are we ever going to get better?
Sergey M Motov, Abu NGA Khan
Published Date: 9 December 2008