Journal ArticleDOI
The biochemistry of natural fasting at its limits.
TLDR
It appears, at least for penguins and seals, that the duration of the fast may be limited by changes that occur in biochemical regulation near the end of theFasts in these animals are closely interrelated.Abstract:
There are several groups of animals that are adapted for extremely long duration fasting as part of their reproductive cycle. Penguins, bears and seals routinely fast without food or water for months at time. However, they do not ‘starve’, as the biochemical implications of starving are very different from those of successful fasting. There are distinct biochemical adaptations in lipid, carbohydrate and especially protein metabolism that allow these animals to survive. It appears, at least for penguins and seals, that the duration of the fast may be limited by changes that occur in biochemical regulation near the end of the fast. In all of these species, the biochemistry of fasting and the ecological and behavioral demands of their breeding cycles are closely interrelated.read more
Citations
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Journal ArticleDOI
Stable isotopes in animal ecology: assumptions, caveats, and a call for more laboratory experiments
TL;DR: The purpose of this communication is to identify the assumptions on which these inferences are based, to characterize the conditions in which they are not met, and to suggest the laboratory experiments that are needed to validate them.
Journal ArticleDOI
Fasting: Molecular Mechanisms and Clinical Applications
TL;DR: In rodents intermittent or periodic fasting protects against diabetes, cancers, heart disease, and neurodegeneration, while in humans it helps reduce obesity, hypertension, asthma, and rheumatoid arthritis.
Journal ArticleDOI
Natural Abundance Variations in Stable Isotopes and their Potential Uses in Animal Physiological Ecology
TL;DR: It is argued that animal physiological ecologists can benefit from including the measurement of naturally occurring stable isotopes in their battery of techniques, and can make an important contribution to the emerging field of stable isotope in biology by testing experimentally the plethora of assumptions upon which the techniques rely.
Journal ArticleDOI
Starvation physiology: reviewing the different strategies animals use to survive a common challenge.
TL;DR: The various physiological strategies that allow different animals to survive starvation are characterized and areas in which investigations of starvation can be improved are identified to facilitate meaningful investigations into the physiology of starvation in animals.
Book ChapterDOI
Tracing aquatic food webs using fatty acids: from qualitative indicators to quantitative determination
TL;DR: Alternative approaches have been developed, which use various types of trophic markers, one of the most promising of these approaches is the use of lipids and fatty acids (FA) to study food web dynamics.
References
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Journal ArticleDOI
Hormone-fuel interrelationships during fasting.
George F. Cahill,M G Herrera,A P Morgan,J S Soeldner,Jurgen Steinke,P L Levy,G A Reichard,D M Kipnis +7 more
TL;DR: Over 50 years ago, Benedict published his extensive monograph on the metabolism of fasting in man, in which he demonstrated that carbohydrate stores provide a small but significant component of the body's fuel for only the first few days.
Book
The Pinnipeds: Seals, Sea Lions, and Walruses
TL;DR: Discusses the adaptation, evolution, classification, distribution, ecology, behavior, communication, and learning of seals, sea lions and walruses.
Journal ArticleDOI
Behavior, biochemistry, and hibernation in black, grizzly, and polar bears
Ralph A. Nelson,G. Edgar Folk join(,Egbert W. Pfeiffer,John J. Craighead,Charles J. Jonkel,Dianne L. Steiger +5 more
TL;DR: For example, the authors showed that black and grizzly bears show four annual physiological stages: Stage I-hibernation, in which lean body mass is preserved and body fat supplies energy; Stage II-walking hibernation, where the biochemistry of hibernation is integrated with physical activity, but food and water intake are minimal; Stage IV-hyperphagia, which increases fat reserves for hibernation.
Book ChapterDOI
The Behavior, Physiology, and Anatomy of Lactation in the Pinnipedia
TL;DR: The bulk of a female’s reproductive expenditure is in an environment in which she cannot feed and the temporal separation of feeding and lactation is achieved by a wide range of behavioral, physiological, and anatomic adaptations.