Average changes in simulated metabolic rates (W) of Whooping Cranes in metabolic-chamber-like environmental conditions across a range of air temperatures (-25°C to 35°C^a) in response to changes in various environmental, physiological, and morphological model parameters.

Metabolic rates are modeled using morphological and physiological properties of the female and male crane measured in this study. Changes for most input parameters are ±10% of values used in modeling Whooping Cranes, so that the sensitivity of model output to different parameters can be compared. The temperature range -25°C to 35°C was chosen to match the range of air temperatures that migratory Whooping Cranes experience in the wilda and thus represent sensitivity analyses most relevant to modeling of real Whooping Cranes. Unless otherwise noted, metabolic-chamber-like conditions include low wind speed (0.01 m/s), low relative humidity (5%), no solar radiation, and ambient air temperatures changing in 1°C intervals. Solar radiation was set to 334.1W to analyze effects of changing solar reflectivity. For these analyses, all thermoregulation mechanisms (e.g. ptiloerection, vasodilation/constriction, panting) were turned off, so that the parameter value being tested would be the only value changing with air temperature. For reference, 1W is 8% of the basal metabolic rate for the simulated female crane and 7% of the basal metabolic rate for a simulated male crane. When metabolic rates drop to 0W within the range of temperatures modeled (S8–S10 Figs), only points with metabolic rates greater than 0 were included in the averages. aThe range of temperatures experienced by wild Whooping Cranes was approximated based on the range of air temperatures occurring at breeding grounds and wintering grounds of the two existing migratory populations of Whooping Cranes, the Eastern Migratory Population and the Aransas-Wood Buffalo Population during times of year when Whooping Cranes are at each location. bMaximum value for reptile skin in lab database. c Minimum value for reptile skin in lab’s database. d Minimum value allowed in model for thermoregulation (See Table 2 for source). eMaximum value allowed in model for thermoregulation (See Table 2 for source). fFor legs entire submerged in water of temperature equal to air temperature. At air temperatures of 0°C and lower, water temperature was held at 0.1°C. Average changes in simulated metabolic rates (W) of Whooping Cranes in metabolic-chamber-like environmental conditions across a range of air temperatures (-25°C to 35°Ca) in response to changes in various environmental, physiological, and morphological model parameters.