Thermal and Feeding Reactions of Pigeons during Food Scarcity and Cold

Abstract

Birds living in the cold face energetic challenges from low ambient temperatures (Ta) as well as from food scarcity which often accompanies cold in nature. Birds react to low Ta with complex thermoregulatory and metabolic adjustments, and they also alter their foraging and feeding behavior rather dramatically when the availability of food becomes limited. In reaching a full understanding of adaptation to cold, it will be necessary to take into account the ways birds adapt to food scarcity as well as their thermal/metabolic adaptations to low Ta. This is a particularly interesting problem because of the interplay between thermoregulation and feeding. For example, when feeding strategies fail to produce sufficent food to maintain energy reserves, some birds reduce energy costs by lowering their body temperature (Tb). Also, exposure to cold not only activates the bird’s thermoregulatory defenses, but alters feeding strategies in a way that results in increased food intake if sufficient food is available in the environment. Furthermore, food intake has short term thermogenic consequences which can be significant in certain circumstances.