A thermal performance curve perspective explains decades of disagreements over how air temperature affects the flight metabolism of honey bees
Data files
Mar 29, 2024 version files 26.87 KB
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Data_Glass_Harrison_2024.xlsx
23.82 KB
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README.md
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Abstract
While multiple studies have shown that honey bees and some other flying insects lower their flight metabolic rates when flying at high air temperatures, critics have suggested such patterns result from poor experimental methods as, theoretically, air temperature should not appreciably affect aerodynamic force requirements. Here, we show that apparently contradictory studies can be reconciled by considering the thermal performance curve of flight muscle. We show that prior studies that found no effects of air temperature on flight metabolism of honey bees achieved flight muscle temperatures that were near or on equal, opposite sides of the thermal performance curve. Honey bees vary their wing kinematics and metabolic heat production to thermoregulate, and how air temperature affects the flight metabolic rate of honey bees is predictable using a non-linear thermal performance perspective of honey bee flight muscle.
README: A thermal performance curve perspective explains decades of disagreements over how air temperature affects the flight metabolism of honey bees
The data in this file come from published data (i.e., Heinrich, 1980; Harrison et al., 2001; Woods et al., 2005; Glass and Harrison, 2022) and a new dataset presented in the main body of the manuscript, which used the honey bee, Apis mellifera. Each study has its separate tab. We digitally extracted data from the figures of the Heinrich, Harrison et al., Woods et al. studies, as these datasets were inaccessible (Heinrich, 1980; Harrison et al., 2001; Woods et al., 2005). Methods for these published studies can be found in each published article, the references for which can be found in the list in the main article. From these previously published studies, we report the free-flying, mass-specific metabolic rates (mW/g) of unloaded bees and their achieved flight muscle temperatures (degrees Celsius) when flown at different air temperatures. We only included unloaded bees weighing < 98 mg in this analysis, which delineation is based on extrapolated values from Woods et al., 2005 (i.e., 90 +/- 8.8 mg; mean +/- S.D., n = 78). By only including bees that weighed < 100 mg, we also ensured the exclusion of bees transitioning from the role of brood care to foraging, which still carry significant hindgut content that can affect flight performance and metabolism (Glass et al., 2021; Glass and Harrison, 2022).
Description of the data and file structure
Each study listed above has its tab.
The Heinrich 1980 study only reported the sample sizes and the mean S.D. for flight metabolism of bees flying at either 20 or 42C air temperature. We report the flight muscle temperature, Tthorax (C), mass-specific metabolic rates as spFRM (mW/g), and calculated all other statistical values based on Heinrich's reported values.
The Harrison et al. 2001 tab included digitally extracted values for flight muscle temperatures, Tthorax (C), and mass-specific flight metabolic rates, spFMR (mW/g), for 'winter bees' flying at 24C air temperature.
The Woods et al. 2005 tab included digitally extracted values for flight muscle temperatures, Tthorax (C), and mass-specific flight metabolic rates, spFMR (mW/g), for honey bees flying across a range of air temperatures from ~18 to 39C, Tair (C).
The Glass & Harrison 2022 data tab reports the mass-specific flight metabolic rates, spFMR (mW/g), air temperature, Tair (C), and flight muscle temperatures, Tthorax (C), of honey bees flying in low-density gas mixtures. The values represent the maximal flight metabolic rates for every half-degree change in flight muscle temperature.
"This study" tab shows the new data presented in our article. On this tab, we report the air temperature, Tair (C), flight muscle temperatures, Tthorax(C), and mass-specific flight metabolic rates, spFMR (mW/g), for honey bees flying across a range of air temperatures (i.e., 20, 30, or 40C).