Physiological Stress in Birds

Abstract

Although the control mechanism is less clearly determined, stress in birds, as in mammals, can be defined in terms of the activation of two integrative neurohumoral systems by external or internal stimuli: (a) the neurogenic system response, which is almost immediate and provides a rapid delivery of energy, and (b) the hypothalamic-pituitary-adrenal complex response, which is a slower, long-term mobilization of defenses. These responses, although temporary defense mechanisms against specific stimuli, place a bird in a state of general nonspecific stress, in which growth rates and resistance to many diseases are diminished.