Light and other Environmental Factors Affecting Avian Reproduction

Abstract

Since most variables in the environment probably affect reproduction in some manner, this discussion obviously must be considerably restricted. As a first restriction, it will be confined to those environmental factors that provide useful information for the basic control of annual reproductive cycles. Special attention will be given to day length and photoperiodic mechanisms, because of their importance in the control of annual cycles in many species of mid- and high latitudes and because of the greater attention that has been directed toward them. As a further restriction, we will give primary consideration to selected natural species, with special attention to the White-crowned Sparrow (Zonorichia leucophrys gambelii), which has been the subject of fairly intensive investigation in our laboratory for the past 15 years. We fully realize that an almost overwhelming fraction of the existing information on avian reproductive physiology has been derived from investigations of domestic species, and that therein reside the interests of a sustantion fraction of the participants of this Symposium. Copyright © 1966. American Society of Animal Science . Copyright 1966 by American Society of Animal Science