| Popis: |
To survive in Antarctica, animals must be tolerant of a wide range of environmental conditions. These include extremely strong winds, the state of water (whether it is liquid or solid) and extreme seasonality, which affects food supply and results in prolonged periods of light or darkness. The Antarctic continent and its surrounding oceans are cold, and animals that are successful must be adapted to survive at extreme temperatures. Terrestrial animals must withstand great daily and seasonal temperature changes, and any adaptations are influenced by the animal’s immediate environment. Daytime summer temperatures on north-facing rock surfaces can reach over 20 °C, while these same rocks in winter can fall to below −40 °C. On a daily basis, terrestrial temperatures in summer can fluctuate by more than 30 °C. By contrast, animals living in the sea have a very constant temperature regime, with temperatures in the Ross Sea at minus 1.9 °C year round (Hunt et al., Antarc Sci 15(3):333–338, 2003). This chapter focuses on ectotherms, animals whose body temperatures match environmental temperature. Endotherms such as penguins and seals, which can regulate their body temperature, also require adaptations for life in Antarctica (Chap. 10), but these are mainly related to staying at a constant, warm body temperature and involve blubber, fur and feathers; similar to what is required by their more northerly cousins. |
