After all, your turkey is not the same wily, energetic, tasty bird that struck our ancestors as the perfect centerpiece for an American holiday.
Although it seems likely that foraging decisions were based upon changes in the energetic requirements of birds, we cannot rule out the possibility that the heavier birds were somehow better able to process toxins at lower temperatures compared to lighter birds, although the possible mechanisms by which this would occur are not clear.
Recess time can be affected by several factors, such as energetic requirements of birds, food availability, insulation of the nest cup and climatic conditions [10], [37].
This would allow us to detect any sudden changes in the birds' energetic states and ability to cope with the decreasing temperature that would be a welfare concern.
Numerous studies have demonstrated that the basal metabolic rate (BMR) and energetic requirements of birds increase as the temperature decreases below their TNZ (e.g. Wunder et al. 1977; Broggi et al. 2004, 2007; Swanson 2010).
Although this could be indicative of lower temperatures increasing the energetic requirements of birds, it could also be that there were fewer alternative prey available or that monarch butterflies were less active or easier to handle on cooler days.
It is believed that the growth and energetic physiology of basalmost birds such as Archaeopteryx were inherited in their entirety from non-avialan dinosaurs.
In general for small birds the energetic costs of molt are high [1],[2], but in large birds the allometry of feather size and feather growth rate results in molting making large time demands on the annual cycle [10].
We predicted that a decrease in temperature would lead to an increased energetic requirement in the birds and that predation of toxic mealworms would also increase.
