Duration of the Regeneration Period of the Internal Reproductive Rhythm in a Xerophilous Equatorial Bird, Quelea quelea

Abstract

THERE exist two widely divergent views on the external means by which the breeding seasons of equatorial birds are regulated. One view is that, although the sexual cycle of at least one such species (Quelea quelea) retains an innate susceptibility to photo-stimulation¹ it is other and various environmental effects (often those arising after rainfall) that operate in conjunction with the internal rhythm and so stimulate breeding irrespective of the cycle of the Sun². The opposing argument³ is that the sexual cycle is governed by photoperiodicity, as is the case in many species living in higher latitudes.