Homeostasis in Desert Reptiles

1. Front Matter

   Pages I-XI

   PDF

2. Introduction

   • S. Donald Bradshaw

   Pages 1-7

3. The Osmotic Anatomy of the Reptiles

   • S. Donald Bradshaw

   Pages 9-19

4. Water and Electrolyte Homeostasis

   • S. Donald Bradshaw

   Pages 21-71

5. Activity and Hormonal Control of Excretory Organs

   • S. Donald Bradshaw

   Pages 73-122

6. Thermal Homeostasis

   • S. Donald Bradshaw

   Pages 123-165

7. Conclusion

   • S. Donald Bradshaw

   Pages 167-173

8. Back Matter

   Pages 175-215

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Deserts, whether hot or cold, are considered to be one of the most difficult environments for living systems, lacking the essential free water which ac­ counts for approximately 60-70% of their body mass and more than 98% of their constituent atoms {Macfarlane 1978}. Amongst vertebrates, reptiles are usually thought of as the animals most adapted or suited to such environments because of their diurnal habit, based on a need for external heat, and their ability to survive far from obvious sources of water. This impression is rein­ forced when one examines the composition of vertebrate faunae characteristic of deserts and arid zones: reptiles predominate and they are often the only vertebrates to be found in hyper-arid areas, such as some parts of the Sahara {Monod 1973}. I recently had occasion to examine this assumption carefully, however, and was led inexorably to the conclusion that reptiles represent a particularly successful desert group, not because of their evolution of superior adaptations, but because of their possession of a basic suite of behavioural and physiologi­ cal characteristics that suit them uniquely to this very resource-limited environment {Bradshaw 1986a}. These fundamental reptilian characteristics are: 1. their low rates of metabolism, compared with birds and mammals, which result in extremely low rates of resource utilisation and lead to considerable economy in the handling of water 2.

• Herpetologie
• Reptilien
• Wüste
• adaptation
• adaption
• desert
• ecophysiology
• environment
• herpetology
• homeostasis
• mammals
• osmoregulation
• physiology
• reptiles
• Ökophysiologie

• The University of Western Australia, Perth, Australia

  S. Donald Bradshaw

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