4. Environmental Stress and Physiological Compensating Mechanisms in Fowl—Temperature and Respiratory Regulation

Abstract

IN LIVING organisms those alterations which favor survival in a changed environment are said to be adaptive (Prosser, 1958) and while adaptation per se does not guarantee survival, the greater the extent of adaptation the more the living material will tend to survive and reproduce itself (Leake, 1964). Adaptation is not a single process but a syndrome and an organism’s adaptive ability depends on the mechanisms which regulate the internal state, its ability to “normalize” after resumption of a nonstress environment, the capability of behavioral adaptive patterns and finally, the ability to survive and continue ontogeny. Because the rates of development and the asymptotic values often differ among the various compensating mechanisms, correlations between them may be difficult and usually only by determining many parameters can one adequately estimate the results of adaptation. Two mechanisms, temperature and respiratory regulation, are examples of this multiparameter approach and show the capabilities of…