TY - JOUR
T1 - Measuring behavioral thermal tolerance to address hot topics in ecology, evolution, and conservation
AU - Camacho, Agustín
AU - Rusch, Travis
AU - Ray, Graham
AU - Telemeco, Rory S.
AU - Rodrigues, Miguel Trefaut
AU - Angilletta, Michael
N1 - Funding Information:
We thank the AZ Game and Wildlife department and US Licenses (SP721353) and IACUC from the Arizona State University (15–1431 R). We are also thankful to E. Turcotte, A. Riley and K. Arshid, among others, for their help during different phases of the study. This project has been funded by FAPESP (project numbers: 15/01300-3 , 13/50297-0 and 12/15754-8 ).
Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2018/4
Y1 - 2018/4
N2 - Understanding the impacts of anthropogenic climate change requires knowing how animals avoid heat stress, and the consequences of failing to do so. Animals primarily use behavior to avoid overheating, but biologists’ means for measuring and interpreting behavioral signs of stress require more development. Herein, we develop the measurement of behavioral thermal tolerance using four species of lizards. First, we adapt the voluntary thermal maximum concept (VTM) to facilitate its measurement, interpretation, and comparison across species. Second, we evaluate the sensitivity of the VTM to diverse measurement options (warming rate, time of day, etc) across four species with highly different life histories. Finally, we clarify the interpretation of VTM in two ways. First, we show the effects of exposure to the VTM on panting behavior, mass loss, and locomotor function loss of two species. Second, we compared the VTM with the preferred body temperatures (PBT) and critical thermal maximum (CTMAX) intraspecifically. We found that the VTM can be consistently estimated through different methods and methodological options, only very slow warming rates affected its estimates in one species. Exposure to the VTM caused panting between 5 and 50 min and induced exceptionally high mass loss rates. Loss of locomotion function started after 205 min. Further, the VTM did not show intraspecific correlations with the PBT and CTMAX. Our study suggests the VTM is a robust and flexible measure of thermal tolerance and highlights the need for multispecies evaluations of thermal indices. The lack of correlation between the VTM, the PBT and CTMAX suggests the VTM may evolve relatively free between the other parameters. We make reccommendations for understanding and using the VTM in studies of ecology, evolution, and conservation.
AB - Understanding the impacts of anthropogenic climate change requires knowing how animals avoid heat stress, and the consequences of failing to do so. Animals primarily use behavior to avoid overheating, but biologists’ means for measuring and interpreting behavioral signs of stress require more development. Herein, we develop the measurement of behavioral thermal tolerance using four species of lizards. First, we adapt the voluntary thermal maximum concept (VTM) to facilitate its measurement, interpretation, and comparison across species. Second, we evaluate the sensitivity of the VTM to diverse measurement options (warming rate, time of day, etc) across four species with highly different life histories. Finally, we clarify the interpretation of VTM in two ways. First, we show the effects of exposure to the VTM on panting behavior, mass loss, and locomotor function loss of two species. Second, we compared the VTM with the preferred body temperatures (PBT) and critical thermal maximum (CTMAX) intraspecifically. We found that the VTM can be consistently estimated through different methods and methodological options, only very slow warming rates affected its estimates in one species. Exposure to the VTM caused panting between 5 and 50 min and induced exceptionally high mass loss rates. Loss of locomotion function started after 205 min. Further, the VTM did not show intraspecific correlations with the PBT and CTMAX. Our study suggests the VTM is a robust and flexible measure of thermal tolerance and highlights the need for multispecies evaluations of thermal indices. The lack of correlation between the VTM, the PBT and CTMAX suggests the VTM may evolve relatively free between the other parameters. We make reccommendations for understanding and using the VTM in studies of ecology, evolution, and conservation.
KW - Behavioral thermal tolerance
KW - CTMAX
KW - Panting
KW - Preferred body temperature
KW - Thermoregulation
KW - Voluntary thermal maximum
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U2 - 10.1016/j.jtherbio.2018.01.009
DO - 10.1016/j.jtherbio.2018.01.009
M3 - Article
C2 - 29549993
AN - SCOPUS:85042713608
SN - 0306-4565
VL - 73
SP - 71
EP - 79
JO - Journal of Thermal Biology
JF - Journal of Thermal Biology
ER -