Chapter 5 Temperature
Body Temperature Regulation Ectotherms Rely mainly on external energy sources. Endotherms - Rely heavily on metabolic energy Homeotherms maintain a relatively constant internal environment. Poikilotherms (= heterotherms) Body temperature varies directly with environmental temperature.
Optimal Photosynthetic Temperatures
Behavioral thermoregulation Figure 7.11
Temperature Regulation by Endothermic Animals Heat gain is mainly generated internally Metabolism or shivering thermogenesis Heat loss is reduced by Morphological change Fat, feather etc Countercurrent exchange
Temperature Regulation by Endothermic Animals Thermal neutral zone is the range of environmental temperatures over which the metabolic rate of a homeothermic animal does not change. Breadth varies among endothermic species. Heat is mainly generated internally Metabolism or shivering thermogenesis
Thermal Neutral Zones
Countercurrent Heat Exchange
Surviving Extreme Temperatures Migration Inactivity Seek shelter during extreme periods. Reducing Metabolic Rate Hummingbirds enter a state of torpor when food is scarce and night temps are extreme. Hibernation - Winter Estivation - Summer
The End