1. Chapter 5
Temperature

9. 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.

11. Optimal Photosynthetic Temperatures

13. Behavioral thermoregulation
Figure 7.11

14. 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

15. 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

16. Thermal Neutral Zones

21. Countercurrent Heat Exchange

22. 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

29. The End