Periodicity of Breeding-Behavior of Three Species of Fairy-wrens (Malurus spp.)

Abstract

Breeding seasons, as determined from nest record cards, for the Superb Malurus cyaneus, Variegated M. lamberti and White-winged M. leucopterus Fairy-wrens were compared within a 30-40°S latitude band and across high to low rainfall zones. All species bred mostly in spring and summer but the Superb Fairy-wrens had the most, and the White-winged Fairy-wrens the least, clearly defined breeding season. Superb Fairy-wrens in high rainfall zones bred in spring and summer but in low rainfall zones their breeding was less seasonal and followed good rains. The Variegated Fairy-wrens bred throughout most of the year in the high rainfall zone although few nests were started in autumn and winter. White-winged Fairy-wrens bred in all months of the year in low rainfall zones but there were few nests in autumn and early winter. With progression towards lower rainfall zones, species may respond opportunistically to good rains falling out of season because rainfall directly affects the amount of available food. White-winged Fairy-wrens may have a lower threshold of response to rainfall than Superb. In addition, breeding stimuli may be hierarchically arranged with increasing photoperiod being most important, followed by rainfall and food.