The role of nest-building activity of gonadotrophin secretions and the reproductive success of ring doves (Streptopelia risoria).

This study was undertaken to investigate the intricate relations between prelaying nest-building activity and preovulatory hormonal changes, and the effects of these events on breeding success. Pairs of ring doves were allowed to go through a complete breeding cycle under four conditions of nest-building opportunity. Nest were self-made, pre-made, pre-made and covered, or removed daily to generate various levels of building activity. Behavioral and hormonal changes were observed throughout the cycle. Blood levels of gonadotrophins were monitored by daily measurements with the method or radioimmunoassay. A depression of follicle-stimulating hormone (FSH) typically was associated with every preovulatory surge of luteinizing hormone (LH); an LH surge not accompanied by a FSH dip was not followed by ovulation. Moreover, the FSH depression was significantly correlated with the level of nest-building activity. These findings led to the proposal that nest-building activity stimulated preovulatory FSH change and, hence, ovulation. The constructed nest in turn appeared to promote incubation behavior. These results are discussed in the context of breeding success.