Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- Adaptation of biological membranes to temperature: biophysical perspectives and molecular mechanisms
- Temperature adaptation: molecular aspects
- Stenotherms and eurytherms: mechanisms establishing thermal optima and tolerance ranges
- Ecological and evolutionary physiology of stress proteins and the stress response: the Drosophila melanogaster model
- Temperature adaptation and genetic polymorphism in aquatic animals
- Phenotypic plasticity and evolutionary adaptations of mitochondria to temperature
- Temperature and ontogeny in ectotherms: muscle phenotype in fish
- Ectotherm life-history responses to developmental temperature
- Testing evolutionary hypotheses of acclimation
- Experimental investigations of evolutionary adaptation to temperature
- Thermal evolution of ectotherm body size: why get big in the cold?
- Physiological correlates of daily torpor in hummingbirds
- Development of thermoregulation in birds: physiology, interspecific variation and adaptation to climate
- Evolution of endothermy in mammals, birds and their ancestors
- The influence of climate change on the distribution and evolution of organisms
- Index
Physiological correlates of daily torpor in hummingbirds
Published online by Cambridge University Press: 04 May 2010
- Frontmatter
- Contents
- List of contributors
- Preface
- Adaptation of biological membranes to temperature: biophysical perspectives and molecular mechanisms
- Temperature adaptation: molecular aspects
- Stenotherms and eurytherms: mechanisms establishing thermal optima and tolerance ranges
- Ecological and evolutionary physiology of stress proteins and the stress response: the Drosophila melanogaster model
- Temperature adaptation and genetic polymorphism in aquatic animals
- Phenotypic plasticity and evolutionary adaptations of mitochondria to temperature
- Temperature and ontogeny in ectotherms: muscle phenotype in fish
- Ectotherm life-history responses to developmental temperature
- Testing evolutionary hypotheses of acclimation
- Experimental investigations of evolutionary adaptation to temperature
- Thermal evolution of ectotherm body size: why get big in the cold?
- Physiological correlates of daily torpor in hummingbirds
- Development of thermoregulation in birds: physiology, interspecific variation and adaptation to climate
- Evolution of endothermy in mammals, birds and their ancestors
- The influence of climate change on the distribution and evolution of organisms
- Index
Summary
Introduction
Hypometabolism is a widespread physiological feature among animals (Hochachka & Guppy, 1987). It can be regarded as an important strategy to overcome fluctuations of environmental parameters, such as cold ambient temperatures, lack of food or water, hypoxia, etc. Temperature, of course, is one of the most important environmental variables directly affecting the energy metabolism of animals, and some of the mechanisms that allow animals to adapt to different ambient temperatures have been extensively investigated over the years (Precht et al., 1973). Endothermy combined with a high body temperature has to a great extent enabled some animals to be fairly independent of environmental temperature fluctuations, either diurnal or seasonal, and has evolved in different Phyla. Insects among the invertebrates, and some fish, some reptiles, birds and mammals among the vertebrates are well known examples of endothermic animals (McNab, 1983). This chapter will focus on some questions involving the temperature relationships as well as the energy metabolism of some birds and mammals that are capable of undergoing a deep metabolic depression within a 24-h cycle, commonly referred to as daily torpor (as opposed to hibernation, referred to as prolonged torpor).
Daily torpor in birds and mammals may be viewed as a well-regulated hypometabolic state which may last up to several hours within a 24-h cycle. It is expressed by a significant reduction of metabolism and body temperature (TB). There are two important requirements for endothermic animals to meet the above definition.
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- Chapter
- Information
- Animals and TemperaturePhenotypic and Evolutionary Adaptation, pp. 293 - 312Publisher: Cambridge University PressPrint publication year: 1996
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