Testing the heat dissipation limitation hypothesis : basal metabolic rates of endotherms decrease with increasing upper and lower critical temperatures

  • Metabolic critical temperatures define the range of ambient temperatures where endotherms are able to minimize energy allocation to thermogenesis. Examining the relationship between metabolic critical temperatures and basal metabolic rates (BMR) provides a unique opportunity to gain a better understanding of how animals respond to varying ambient climatic conditions, especially in times of ongoing and projected future climate change. We make use of this opportunity by testing the heat dissipation limit (HDL) theory, which hypothesizes that the maximum amount of heat a species can dissipate constrains its energetics. Specifically, we test the theory’s implicit prediction that BMR should be lower under higher metabolic critical temperatures. We analysed the relationship of BMR with upper and lower critical temperatures for a large dataset of 146 endotherm species using regression analyses, carefully accounting for phylogenetic relationships and body mass. We show that metabolic critical temperatures are negatively related with BMR in both birds and mammals. Our results confirm the predictions of the HDL theory, suggesting that metabolic critical temperatures and basal metabolic rates respond in concert to ambient climatic conditions. This implies that heat dissipation capacities of endotherms may be an important factor to take into account in assessments of species’ vulnerability to climate change.

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Author:Imran Khaliq, Christian Hof
Pubmed Id:https://pubmed.ncbi.nlm.nih.gov/30402344
Parent Title (English):PeerJ
Publisher:PeerJ, Inc.
Place of publication:London [u. a.]
Contributor(s):Amanda Bates
Document Type:Article
Year of Completion:2018
Date of first Publication:2018/10/31
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2018/12/11
Tag:BMR; Birds; Endogenous heat load; Energy; Macrophysiology; Mammals; Metabolic critical temperatures
Page Number:13
First Page:1
Last Page:13
Distributed under Creative Commons CC-BY 4.0
Institutes:Angeschlossene und kooperierende Institutionen / Senckenbergische Naturforschende Gesellschaft
Biowissenschaften / Institut für Ökologie, Evolution und Diversität
Fachübergreifende Einrichtungen / Biodiversität und Klima Forschungszentrum (BiK-F)
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie
Licence (German):License LogoCreative Commons - Namensnennung 4.0