Effect of Winter Temperature on Wild Turkey Metabolism

We used indirect calorimetry to measure the effects of air temperature (Ta), age class, and body mass on metabolic rates of 9 adult and 7 juvenile female eastern wild turkeys (Meleagris gallopavo silvestris) during winter. Previous studies produced disparate results on this important aspect of winter ecology of wild turkeys. Standard metabolic rates (SMRs) of adult and juvenile hens were not different (P = 0.122) and averaged 28.69 mL$\text{min}^{-1}\cdot \text{bird}^{-1}$. Wild turkey metabolism increased with decreasing Ta(P < 0.001) below the lower critical temperature ($\text{T}_{\text{1c}}$) of 10.9°C. Metabolic rates were not related to body mass (P = 0.571), and age-specific metabolic rates were not distinguishable (P = 0.998). We estimated that a flock of 20 hens would need to find 400 g/day of additional food to meet thermoregulatory demands for each 10°C drop in Tabelow 10.9°C.